Podcasts about lqts

This week's episode is a replay from 2019 of a 'co-branded' episode with the SADS Foundation (SADS.ORG) and we speak with the founder and director of Crediblemeds.org, Professor of Medicine Ray Woosley of the University of Arizona. Dr. Woosley speaks with us about how he started the first website dedicated to assessing the evidence for drugs' impact on the QT interval establishing a reliable and trusted website for clinicians and patients to visit to learn about possible drug interactions and their impact on LQTS and the QT interval in general. How was the site first conceived? What are the latest changes on the site? What are the plans for this work going forward? Is grapefruit juice really dangerous? Why does the site request that all have to sign up to access the site? Professor Woosley provides all the answers and more this week!

This week in a replay of a previous co-branded episode with the SADS Foundation (SADS.ORG) from 2.5 years ago, we speak with Professor Peter Schwartz of University of Pavia about a recent work he authored on the topic of changes in repolarization amongst well trained athletes. Can athletic training masquerade as LQTS causing prolongation and/or abnormalities in the QT interval? How can these patients be properly identified and not 'lumped' into the LQTS 'pile'? This is a very important work by one of the foremost authorities on the planet on LQTS and Professor Schwartz also shares with us how he became interested in this topic 50+ years ago as well as some pearls for clinical investigators at the start of their careers. One of the best and most inspirational interviews of the entire nearly 250 episode series! doi: 10.1161/CIRCULATIONAHA.120.048916

This week's episode of the podcast is supported by the SADS Foundation (SADS.ORG) and is on the topic of the overdiagnosis of LQTS. What sorts of conditions can lengthen the QT interval without true congenital LQTS syndrome? What are the most common errors of ECG interpretation that account for misdiagnosis of this condition and are there leads of the ECG that might help or hurt when attempting to accurately measure the QT interval. What is the role of the ICD in the LQTS patient? We speak with Professor of Pediatrics, Medicine and Pharmacology at the Mayo Clinic Alix School of Medicine, Dr. Michael Ackerman about a recent work he published on this important topic.doi: 10.1016/j.jacc.2022.11.036.

How can a mother, grandmother, and great-grandmother -- determine how to help families like her own? Why would a woman make it her mission to help others with an invisible illness? What can we learn from such a woman?Jackie Renfrow thought her family had a history of epilepsy. After losing her son Jimmy in 2000 and her daughter Crissy in 2002, she was desperate to find a way to save her two baby granddaughters. It wasn't until her own mother started fainting and having irregular heartbeats that she finally got answers. Emergency doctors performed an electrocardiogram (ECG) and promptly diagnosed her with Long Q-T syndrome. Jackie and her granddaughters Alexis and Jessica also had an ECG and they were diagnosed with the syndrome as well. Jackie has since started a chapter of the Sudden Cardiac Arrest Association in Indianapolis. She works with scientists, doctors, parents, and others to promote awareness of sudden cardiac arrest and access to defibrillation and treatment. In honor of her children and grandchildren, she works to spread awareness of Long Q-T syndrome in order to help other families prevent the loss of their loved ones.  In this episode, Jackie talks with Anna about what she has learned in living with Long Q-T Syndrome and seeing it affect generations of her family.Link mentioned in this episode: Jackie's first appearance on "Heart to Heart with Anna" -- https://www.buzzsprout.com/62761/398945-seizing-the-day-with-jackie-renfrowJackie's appearances on "Heart to Heart with Michael"Losing Loved Ones to a Misdiagnosis: https://www.buzzsprout.com/123208/1101869Living with Loss after Loss: https://www.buzzsprout.com/123208/1133858SADS Foundation: www.sads.orgSudden Cardiac Arrest Association: https://suddencardiacarrest.org/Anna's Buzzsprout Affiliate Link (if you'd like to try Buzzsprout for your podcast and get a bonus gift card -- and Anna will, too!) use this link: https://www.buzzsprout.com/?referrer_id=16817Links to 'Heart to Heart with Anna' Social Media and Podcast Pages:Apple Podcasts: https://itunes.apple.com/us/podcast/heart-to-heart-with-anna/id1132261435?mt=2MeWe: https://mewe.com/i/annajaworskiFacebook: https://www.facebook.com/HearttoHeartwithAnna/Instagram: https://www.instagram.com/hearttoheartwithanna/Twitter: https://twitter.com/AnnaJaworskiYouTube: https://www.youtube.com/channel/UCGPKwIU5M_YOxvtWepFR5ZwInstagram: https://www.instagram.com/hearttoheartwithanna/ Website: https://www.hug-podcastnetwork.com/Support the show (https://www.patreon.com/HearttoHeart)

This week, in a co-branded episode with SADS.ORG, we speak with Professor Michael Ackerman of The Mayo Clinic about a recent work he published with his team on a novel AI model to assess the ECG for the diagnosis of LQTS. How accurately can this technology identify a patient with LQTS? Can it identify the genetic diagnosis from the ECG alone? What are the implications of this sort of technology in regards to screening patients for LQTS? These are amongst the many topics reviewed with Dr. Ackerman this week on the podcast. doi: 10.1001/jamacardio.2020.7422

In this episode of the Heart podcast, Dr James Rudd is joined by Dr Greg Mellor from Royal Papworth Hospital, Cambridge. They discuss LQTS, Brugada and CPVT syndromes - diagnosis, risk stratification, patient education and therapeutic options. If you enjoy the show, please subscribe to the podcast to get episodes automatically downloaded to your phone and computer. Also, please consider leaving us a review at https://itunes.apple.com/gb/podcast/heart-podcast/id445358212?mt=2 Link to published paper: https://heart.bmj.com/content/early/2021/02/14/heartjnl-2019-316026

This week in a co-branded episodes with the SADS Foundation (SADS.org) we speak with Professor Johannes von Alvensleben of U. Colorado about a recent PACES study on the outcomes of S-ICD's in children and ACHD patients. What are the challenges to their use and who is a good candidate? What is involved in screening patients for an S-ICD and why do children and ACHD patient seem to 'screen out' more than the general population? What are the challenges to their implantation and what is coming down the pipeline in terms of innovation with these devices? Dr. von Alvensleben shares his insights this week. doi: 10.1016/j.jacep.2020.07.010

This week in a co-branded episode with the SADS Foundation (SADS.ORG), we speak with Professor Peter Schwartz of University of Pavia about a recent work he authored on the topic of changes in repolarization amongst well trained athletes. Can athletic training masquerade as LQTS causing prolongation and/or abnormalities in the QT interval? How can these patients be properly identified and not 'lumped' into the LQTS 'pile'? This is a very important work by one of the foremost authorities on the planet on LQTS and Professor Schwartz also shares with us how he became interested in this topic 50+ years ago as well as some pearls for clinical investigators at the start of their careers. One of the best and most inspirational interviews of the entire 150 episode series! doi: 10.1161/CIRCULATIONAHA.120.048916

Paul J. Wang: Welcome to the monthly podcast! On the Beat for Circulation: Arrhythmia and Electrophysiology. I'm Dr. Paul Wang, Editor-in-Chief. With some of the key highlights from this month's issue. Paul J. Wang: In our first paper, Demilade Adedinsewo and associates assess the accuracy of an artificial intelligence-enabled electrocardiogram [AI-ECG] to identify patients presenting with dyspnea who have left ventricular LV systolic function (defined as LV ejection fraction ≤35%) in the emergency department [ED]. Patients were included if they had at least one standard 12-lead electrocardiogram [ECG] acquired on the date of the ED visit and an echocardiogram performed within 30 days of presentation. Patients with prior LV systolic dysfunction were excluded. A total of 1,606 patients were included. Meantime from ECG echocardiogram was one day. The AI-ECG algorithm identified LV systolic dysfunction with an area under the curve [AUC] of 0.89 and accuracy of 85.9%. Sensitivity was 74%, specificity 87%, negative predictive value 97%, and positive predictive value 40%. To identify an ejection fraction less than 50%, the AUC was 0.85, sensitivity 86%, sensitivity 63%, and specificity 91%. NT-proBNP alone with a cutoff greater than 800 identified LV systolic function with an AUC of 0.80 by comparison. Paul J. Wang: In our next paper, Mahmood Alhusseini and associates hypothesize that convolutional neural networks [CNN] may enable objective analysis of intracardiac activation in atrial fibrillation [AF]. They perform panoramic recording of bi-atrial electrical signals in AF and use the Hilbert-transform to produce 175,000 image grids in 35 patients labeled for a rotational activation by experts who showed consistency, but with variability (kappa [κ]=0.79). In each patient, ablation terminated atrial fibrillation. A CNN was developed and trained on 100,000 AF image grids validated on 25,000 grids, and then tested on a separate 50,000 grids. They found in a separate test cohort of 50,000 grids, CNN reproducibly classified AF image grids into those with or without rotational sites with 95.0% accuracy. This accuracy exceeded that of support vector machines, traditional linear discriminant, and k-nearest neighbor statistical analyses. To probe the CNN, they applied gradient weighted class activation mapping, which revealed that the decision logic closely mimicked rules used by experts (C statistic 0.96). The authors concluded that convolutional neural networks improve the classification of intercardiac AF maps compared to other analyses and agreed with expert evaluation. Paul J. Wang: In our next paper, Kenji Okubo and associates examined whether late potential LP, abolition and ventricular tachycardia [VT] non-inclusive ability predicted long-term outcomes in patients with non-ischemic cardiomyopathy [NICM] undergoing VT ablation. The total 403 patients with NICM (523 procedures) who underwent VT ablation from 2010 to 2016 were included. The underlying structural disease consists of dilated cardiomyopathy (DCM, 49%), arrhythmogenic right ventricular cardiomyopathy (ARVD 17%), postmyocarditis (14%), valvular heart disease (8%), congenital heart disease (2%), hypertrophic cardiomyopathy (2%), and others (5%). Epicardial access was performed in 57% of patients. At baseline, the LPs were present in 60% of patients, and a VT was either inducible or sustained/incessant in 85% of the cases. At the end of the procedure LP abolition was achieved in 79% of cases in VT noninducability in 80%. After a multivariate analysis, the combination of LP abolition and VT noninducibility was independently associated with free survival from VT (hazard ratio, 0.45, p = 0.0002) and cardiac death (hazard ratio 0.38, P = 0.005). The benefit of LP abolition of preventing the VT recurrence in ARVD and postmyocarditis appeared superior to that observed for DCM. Paul J. Wang: In our next paper, Domenico Corradi, Jeffrey Saffitz and associates hypothesize that structural molecular changes in atrial myocardium that correlate with myocardial injury and precede and predict postoperative atrial fibrillation [POAF] may identify new molecular pathways and targets for prevention of this common morbid complication. Right atrial appendage [RAA] samples were prospectively collected during cardiac surgery from 239 patients enrolled in the OPERA trial. 35.2% of patients experienced POAF compared to the non-POAF group. They were significantly older and more likely to have chronic obstructive pulmonary disease or heart failure. They had a higher Euro score and more often underwent valve surgery. No differences in atrial size were observed between POAF and non-POAF patients. The extent of atrial interstitial fibrosis, cardiomyocyte myocytolysis, cardiomyocyte diameter, glycogen storage, or connection 43 distribution at the time of surgery, was not significantly associated with the incidents of POAF. None of these histopathological abnormalities were correlated with level of NT pro-BNP, hs-cTnT, CRP, or oxidative stress biomarkers. The authors concluded that in sinus rhythm patients undergoing cardiac surgery, histopathological changes in RAA do not predict POAF. They did not also correlate with biomarkers of cardiac function, inflammation, and oxidative stress. Paul J. Wang: In our next paper, Mark McCauley, Liang Hong, Arvind Sridhar, and associates hypothesize that obesity decreases sodium channel NAF 1.5 expression via enhanced oxidative stress, thus reducing the sodium current and enhancing susceptibility to atrial fibrillation [AF]. They studied a diet induced obese [DIO] mouse model. Pacing induced AF in 100% of DIO mice versus 25% in controls (P 20 ms shorter than the other sites, and/or induction of AF/atrial tachycardia during measurements. LVA ablation was performed in the LA-LVA patients during the follow-up period of a mean of 62 weeks, the EP test-guided group had a significantly lower recurrence rate (19%,11/57 versus 41%, 22/54, P=0.012) and a higher Kaplan-Meier AF/AT-free survival curve compared with controls (P=0.01). No significant differences in the recurrence, and AF/AT-free survival curves between PWI (positive EP test) and non-PWI (negative EP test) subgroups were observed. Therefore, PWI for positive EP tests reduced the AF/AT recurrence in the EP test-guided group. A stepwise Cox proportional hazard analysis identified EP test-guided ablation as a factor, reducing recurrence rates. The recurrence rates in LA-LVA ablation group and EP test-guided group were similar. Paul J. Wang: In our next study, Jinxuan Lin and associates assess whether simultaneous pacing of the left and right bundle branch areas may achieve more synchronous ventricular activation than just bundle pacing alone. In symptomatic bradycardia patients, the distal electrode of the bipolar pacing lead was placed at the left bundle branch area via a transventricular-septal approach. This was used to pace the left bundle branch area, while the ring electrode was used to pace the right bundle branch area. Bilateral bundle branch area pacing [BBBP] was achieved by stimulating the cathode and anode in various configurations. BBBP was successfully performed in 22 out of 36 patients. Compared with LBBP, BBBP resulted in greater shortening of QRS duration (109.3 vs 118.4 ms, P < 0.001). LBBP resulted in paced RBBB configuration with a DRVAT of 115 ms and interventricular conduction delay of 34.0 ms. BBBP fully resolved the RBBB morphology in 18 patients. In the remaining 4 patients, RBBP pacing partially corrected the right bundle branch block. Paul J. Wang: In our next paper, Ramanathan Parameswaran, Jonathan Kalman, Geoffrey Lee and associates recorded 2-minute long segments of simultaneous inter-operative mapping of endo- and epicardial lateral right atrial [RA] wall in patients with persistent atrial fibrillation [AF] using 2 high-density grid catheters (16 electrodes, 3 mm spacing). Filtered unipolar and bipolar electrograms [EGMS] of continuous 2-minute AF recordings and electrodes locations were exported for phase analysis. They defined endocardial-epicardial dissociation [EED] as phase differences of ≥20 ms between paired endo- and epi electrodes. Wavefronts [WF] were classified as single rotations, that is single wavefront, focal waves, or disorganized activity as per standard criteria. Endo-Epi wave fronts were simultaneously compared on dynamic phase maps. Complex fractionated electrograms were defined as bipolar electrograms with directional changes occupying at least 70% of the sample area. 14 patients with persistent AF underwent cardiac surgery are included. EED was seen in 50.3% of phase maps with significant temporal heterogeneity. Disorganized activity (endo 41.3%, epi 46.8%, P = 0.0194) and single wave (endo 31.3 versus epi 28.1, P = 0.129) were the dominant patterns. Transient rotations (endo 22%, epi 19.2%, P = 0.169, mean duration 590 ms) and non-sustained focal waves (endo 1.2% and epi 1.6%, P = 0.669) were also observed. Apparent transmural migration of rotational activations (n=6) from the epi- to the endocardium was seen in 2 patients. EGM fractionation was significantly higher in the epicardium than endocardium (61.2% versus 51.6%, P < 0.0001). The authors concluded that simultaneous endo-epi phase mapping of prolonged human persistent AF recordings showed significant EED marked temporal heterogeneity, discordant and transitioning wavefronts patterns and complex fractionations. No sustained focal activity was observed. Such complex 3-dimensional interactions provide insights into why endocardial mapping alone may not fully characterize the AF mechanism and why endocardial ablation may not be sufficient. Paul J. Wang: In our next paper, Andrew Beaser and associates hypothesize that intravascular ultrasound [IVUS] could accurately visualize and quantify intravascular lead adherence and degree of intravascular lead adherence correlates with transvenous lead extraction difficulty. Serial imaging of leads occurred prior to transvenous lead extraction using IVUS. Intravascular lead adherence areas were classified as high or low grade. Degree of extraction difficulty was assessed using 2 metrics and correlated with intravascular lead adherence grade. Lead extraction difficulty was calculated for each patient and compared to IVUS findings. 158 vascular segments in 60 patients were analyzed: 141 (89%) low grade versus 17 (11%) high grade. Median extraction time (low = 0 versus high grade 97 seconds, P < 0.001) and median laser pulsations delivered (low = zero versus high grade 5,852, P < 0.001) were significantly higher in the high-grade segments. Most patients with low lead extraction difficulty score had low intravascular lead adherence grades. 86% of patients with high lead extraction difficulty score had low IVUS grade, and the degree of transvenous lead extraction difficulty was similar to patients with low IVUS grades and lead extraction difficulty scores. Paul J. Wang: In our next paper, András Bratincsák, and associates sought to create the foundation of normative ECG standards in the young using Z-scores. 102 ECG variables were collected from a retrospective cohort of 27,085 study subjects with no known heart conditions, age zero to 39 years. The cohort was divided into 16 age groups by gender. Median interquartile range and range were calculated for each variable adjusted to body surface area. Normative standards were developed for all 102 ECG variables, including heart rate; P, R, and T axis; R-T axis deviation; PR interval, QS duration, QT, and QTc interval; P, Q, R, S, and T amplitudes in 12 leads; as well as QRS and T wave integrals. Incremental Z-score values between negative 2.5 and 2.5 were calculated to establish the upper and lower limits of normal. Historical ECG interpretive concepts were reassessed and new concepts observed. The author summarized that electronically acquired ECG values based on the largest pediatric and young adult cohort ever compiled provide the first detailed, standardized, quantitative foundation of traditional and novel ECG variables. Paul J. Wang: In our next paper, Jungmin Hwang and associates hypothesize that suppressing the late sodium current may counterbalance the reduced repolarization reserve in long QT syndrome [LQTS] and prevent early depolarization [EAD] and polymorphic ventricular tachycardia [PVT]. They tested the effects of selective late sodium channel blocker GS967 on polymorphic ventricular tachycardia [PVT] induction in a transgenic rabbit model of type two using intact heart optical mapping, cellular electrophysiology, and confocal calcium imaging and computer modeling. They found that GS967 reduced ventricular fibrillation [VF] induction under a rapid pacing protocol (7 out of 14 hearts in control versus 1 out of 14 at 100 nanomolar) without altering action potential duration [APD] or restitution and dispersion. GS967 suppressed PVT incidents by reducing calcium mediated EADs and focal activity during isoproterenol perfusion (at 30 nanomolar, 7 out of 12 and a 100 nanomolar, 8 out of 12 without EADs and PVTs). Confocal calcium imaging of LQT myocytes revealed GS967 shortened calcium transient duration by accelerating sodium calcium exchanger mediated calcium efflux from cytosol, thereby reducing EADs. Computer modeling revealed the inward late sodium current potentiates EADs in the LQT setting through providing additional depolarizing currents through action potential plateau phase, and increasing intracellular sodium that decreases the depolarizing sodium calcium exchanger, thereby suppressing the action potential plateau and delaying the activation of slowly activating delayed rectifier current, IKS. Suggesting important roles in the late sodium current in regulating intracellular sodium. Thus, the authors concluded that selective late sodium channel blockade by GS967 prevents EADs and abolishes PVT in LQT rabbits by counterbalancing the reduced repolarization reserve and normalizing intracellular sodium. Paul J. Wang: In our next paper, Pietro Lazzerini, Mohamed Boutjdir and associates, hypothesize that systemic inflammation per se can significantly prolong QTc during infection via cytokine-mediated changes in potassium channel expression. They found in patients with acute infections, regardless of concomitant QT-prolonging anti-microbial therapy, QTc was significantly prolonged but rapidly normalized in parallel to C-reactive protein [CRP] and cytokine level reduction. Consistently, in Torsades de Pointes cohort, concomitant acute infections were prevalent 30% despite only a minority (25%) of these cases were treated with QT-prolonging anti-microbials. KCN J2, potassium channel expression in peripheral blood mononuclear cells was strongly correlated to that in ventricles, inversely associated to CRP and interleukin one changes in acute infection patients. The authors concluded that acute infection, systemic inflammation rapidly induces cytokine-mediated ventricular electrical remodeling and significant QTc prolongation, regardless of concomitant antimicrobial therapy. Paul J. Wang: In a research letter, Christophe Beyls and associates examined the risk of bradycardia and critically ill COVID-19 patients treated with Lopinavir [LPV], a protease inhibitor of HIV-1, and Ritonavir [RTV], another protease inhibitor that strongly inhibits hepatic cytochrome P 450 [CYP3A4] activity in order to increase the Lopinavir plasma concentration. During the first month of the outbreak, patients admitted to the ICU with positive PCR for COVID-19 received LPV (200 mg)/RVT (50 mg) twice daily for 10 days. Bradycardia was defined as heart rate below 60 for a period of more than 24 hours. All patients were monitored 24 hours a day for all hemodynamic parameters, including heart rate with a five-lead ECG. Monitors were linked to a computerized system allowing to extract hemodynamic data. LPV/RTV plasma concentration was monitored using analytic method, combining high propensity performance, liquid chromatography and tandem mass spectrometry at 72 hours and every 72 hours. They prospectively included 41 COVID-19 patients who received LPV/RTV treatment. Nine or 22% patients experienced bradycardia. No patients had a pre-existing nodal pathology on the ECG on admission. Among the 9 patients with bradycardia, 8 or 88% were sinus bradycardia and one (12%) third-degree AV block. Causality may be considered as bradycardia occurred at least 48 hours after LPV/RTV initiation, bradycardia resolved after discontinuation or dose reduction and no alternative cause was found. Patients who presented with bradycardia were older, had a higher RTV plasma concentration and a lower lymphocyte count. In our study, no correlation was found between RTV plasma concentration, LPV plasma concentration, and mean heart rate at day three. No patient had bradycardia in the first 48 hours after LPV/RTV administration. For patients with LPV RTV plasma level overdose, the dose of LPV RTV was divided by two until the next dose. For the patient with third degree AV block LPV/RTV was stopped. None of the patients had any known cytochrome CYP3A4-inhibiting drugs. The authors concluded that the results suggest that RTV plasma overdose in elderly critical ill patients may increase the risk of bradycardia. Paul J. Wang: In a research letter, Emily Zeitler and associates surveyed cardiac implantable device [CID] patients. A total of 109 patients were approached to participate, nine declined. Most respondents were white (79%), male (60%) with a mean age of 73 years. The median number of correct responses to the 11 factual questions was six. Respondents held some common misconceptions. For example, 25% of respondents believe that FDA determines the cost of the device. Trust in the FDA was high; 67% of respondents agreed "I trust the FDA". Respondents mostly agreed "the FDA would not approve my device unless it was a hundred percent safe". Only 6% of respondents agreed, "we would be better off if there was no FDA," and a similarly small fraction disagreed with "when it comes to medical devices, the U.S. does the best job in the world at keeping people safe". Most respondents, 69% demonstrated fear of device recalls by agreeing with "if there was a recall of all are part of my device, I think I would be worried or scared." On average, respondents were comfortable sacrificing some privacy for device surveillance, 75% agreed with "once the device has been approved, the FDA should continue to monitor for signs that there are problems with the device even if it means that private health information about me is collected". Respondents seemed to believe that the FDA was risk averse; 56% believed that the FDA does not approve devices unless they're a hundred percent safe. This is in contrast to trends shifting the demonstration of safety to post-approval settings and expanding acceptable forms of data for regulatory approval. Paul J. Wang: In a research letter, Laura Rottner, Christoph Sinning and associates examined novel high resolution imaging system based on a wide band dielectric technology, and reports the first clinical experience of feasibility and reliability of cryoballoon [CB] occlusion tool as compared to fluoroscopic and 3D transesophogeal [TEE] assessment during pulmonary vein isolation [PVI]. In consecutive patients with symptomatic atrial fibrillation [AF], cryoballoon-based ablation was performed with a novel 3D wide-band dielectric imaging system. Pulmonary vein [PV] occlusion was assessed with fluoroscopy in 3D-TEE and concomitantly correlated with the novel CB occlusion tool. The endpoint was defined as persistent PV isolation verified by spiral mapping catheter recordings 30 minutes after the last CB application. A total of 36 (90%) of PVs in 10 patients with paroxysmal (40%) and persistent (60%) were analyzed. In all patients, a normal PV anatomy with four separate PVs was documented. Visualization via 3D-TEE was feasible in 80% septal PVs and 100% of lateral PVs. In 67% of PVs, total PV occlusion was confirmed by all 3 imaging modalities. In 17% of PVs, incomplete PV occlusion was initially demonstrated by TEE and 3D dielectric imaging, whereas fluoroscopy suggested complete occlusion in initial analysis. After repositioning of the CB at 3 PVs, complete PV occlusion was verified by all three modalities. In 3 out of 36 (8%), no occlusion was initially seen by any imaging modality, for which the CB was repositioned resulting in total PV occlusion as confirmed by all three modalities. Two out of 36 PVs (6%) were confirmed to be occluded via fluoroscopy in 3D-TEE, but not by the CB occlusion tool. There was only one out of 36 PVs (3%), which were confirmed to be included by the CB tool and 3D-TEE, but not by fluoroscopy. A negative and positive predictive value of 1.0 and 0.6 was seen when comparing PV occlusion by the novel occlusion tool compared to PV collusion, verified by fluoroscopy and 3D-TEE. Paul J. Wang: In a special report, Jun Hirokami, and associates aim to clarify the spatial correlations between fractionated potential detected by Lumipoint with non-PV trigger. They enrolled 30 symptomatic atrial fibrillation [AF] patients who underwent non pulmonary vein [PV] foci ablation. 4 patients underwent the first procedure, 17 underwent second procedure and eight underwent third procedure, and one underwent a fourth procedure. They highlighted the fractionated signal area in atrial muscle [FAAM] during sinus rhythm and atrial pacing, thereby producing a digital FAAM map. They retrospectively applied Lumipoint to 30 patients in order to clarify the relationship between FAAM and non-pulmonary vein [PV] foci. Non-PV foci were successfully identified in all patients. They identified four patients with multiple non-PV foci. Of these four patients, one had non-PV foci at the superior vena cava and left arterial anterior wall. One had non-PV foci at the SVC and LA bottom wall. And two had non-PV foci at the SVC and interatrial septum. They only analyze 30 non-PV foci unrelated to SVC because the SVC isolation was routinely performed for non-PVC foci at the SVC. In order to analyze the correlation between FAAM and location of non-PV triggers, they determined the cutoff points of peaks slider, which non-PV triggers were completely located within the FAAM in. The accuracy of predicting location of the non-PV triggers was summarized using area under the receiver operating curve, a UROC curve. The optimal cutoff point of peak sliders to predict the location of non-PV was determined by the Youden Index. The Youden Index established the optimal cutoff point of the maximum peaks slider was 7; sensitivity was 0.906 and specificity 0.770. The peaks slider 7 was the most accurate predictor fractionated signals location area to the location of non-PV triggers. (area under the curve 0.902). The mean area of peaks slider 7 was six centimeters squared or 4.3% of the atrium. The authors concluded that the proof-of-concept observational study demonstrated that novel visualization tool of FAAM map successfully identified non-PV triggers that did not induce atrial fibrillation and/or non-PV foci, which potentially serve as substrates for AF maintenance. Paul J. Wang: In a special report, Leslie Saxon and associates update their prior publication providing further detail on mitigation adoption rates for the entirety of the U.S. patient population with implanted cardiac rhythm management devices falling under FDA cyber security advisories from any device manufacturer. They also provided limited data on known cybersecurity mitigation adoption outside the U.S. They report a unique complication resulting for introducing firmware to already implanted devices. Discuss how evolving FDA policies towards firmware mitigation adoption may increasingly determine how and when updates occur. They found that patients under 50 years of age and those over 80 years were less likely to receive the software upgrades, and male versus females had greater rates of upgrades. The upgrade rates varied according to U.S. Region and date of implant. Resynchronization devices were less likely to receive the upgrade, as were pacemaker dependent patient. Those ICD patients initially falling under the battery advisers were upgraded more frequently. The number of advisory patients followed in clinic was a significant predictor for firmware upgrade adoption, particularly for pacemakers that were often upgraded in smaller size clinics. Overall, only 24% of devices for all groups, and 22% of devices not impacted by the battery advisory were upgraded. For Abbott devices, the home communicator cyber security vulnerabilities were mitigated with an automatic software patch that was updated using the Merlin network, and adoption rates were nearly a hundred percent. For the entire patient cohort with impacted pacemaker and ICDs, U.S. and global adoption rates remain low at 24 to 35% with a low rate of complications. Most reported complications for pacemakers and ICD were symptoms (transient palpitations, dizziness, or syncope) that resulted from the temporary change in mode to VVI or transient loss of programmer telemetry while performing the upgrade (pacemaker 0.05%; ICD 0.01%). Globally, a total of 9 pacemakers and 8 ICDs required replacement, as a result of performing the firmware upgrade due to irreversible reversion to a backup pacing mode and loss of defibrillation therapy (ICDs). Analysis of the returned ICD pulse generaotrs found at 7 cases, the cause related to a capacitor bond failure that was exposed only when extended telemetry as required by the upgrade. The failure mechanism was an isolated component failure in the remaining ICD. The programmer based test has recently been FDA approved and can be performed prior to firmware upgrade to identify ICD patients at risk for capacitor bond failure. A total of 256 ICDs were susceptible to loss of RF telemetry after receiving a firmware update, and this has since been mitigated with a software patch. For Medtronic programmers, the initial mitigation responses of cybersecurity advisory was to take the programmers off the network. The network connection was enhanced with one or more security protections provided to the programmers using a flash drive, so the programmers can now be secured from potential cyber intrusion when connected to the network. Medtronic ICDs are currently being upgraded. The upgrade is being provided to impacted patients automatically when the device is interrogated with the programmer during follow-up. Metronic is introducing upgrades in phased approach with all expected to be completed by the beginning of 2021. There are 9% or 55,000 ICDs under this advisory that cannot receive the update due to design or safety constraints. Since the 2017 Abbott advisories identify cybersecurity vulnerabilities in pacemakers and ICDs with the potential for exploits have been increased, including 2 additional FDA advisories issued for another manufacturer. Medtronic's connected communication product and implantable defibrillators in the past 12 months. The authors comment that a recent report and a smaller number of Abbott impacted pacemaker and ICD patients from Canada reported marked differences in mitigation adoption rates between pacemakers and ICDs. This was due to an increase incremental clinical familiarity and comfort with performing the updates as experience and education surrounding these issues evolve. The authors indicate that automating cybersecurity updates without process in place for determining safety, for alerting patients or clinicians that have been delivered, may also be associated with yet unknown risks. Newer generation devices and communication protocols may render cyber security, advisories less frequent as cybersecurity integration is considered an essential aspect of device design. Paul J. Wang: In a review article, Albert Feeny and associates discuss the use of artificial intelligence [AI] and machine learning [ML] in medicine, which are currently areas of intense exploration showing potential to automate human tasks or even perform tasks beyond human capabilities. The first objective of this review is to provide the novice reader with a literacy of AI/ML methods, and to provide a foundation of how one may conduct an ML study. The review provides a technical overview of some of the most commonly used terms, challenges in AI/ML studies with reference to recent studies in cardiac electrophysiology to illustrate key points. The second objective of this review is to use examples from the recent literature to discuss how AI and ML are changing clinical practice and research in cardiac electrophysiology with emphasis on disease detection and diagnosis, prediction, and patient outcomes and novel characterization of disease. The final objective is to highlight important considerations and challenges for appropriate variation, adoption, and deployment of AI technologies and practice. Paul J. Wang: That's it for this month! We hope that you will find the journal to be the go-to place for everyone interested in the field! See you next time! This program is copyright American Heart Association 2020. Thank you.  

Can we discover new therapies for the heart with stem cells? From finding safer medication to preventing cardiac arrest, experts share the latest in the field of cardiac stem cell research. Moderated by Anthony DeMaria, MD, UC San Diego Pat Farrant: Patient Perspective Deepak Srivastava, MD, Gladstone Institutes: Cellular Reprogramming Approaches for Heart Disease Mark Mercola, PhD, Stanford University: Induced Pluripotent Stem Cell (iPSC)-derived Cardiomyocytes for Predicting and Removing Drug Cardiotoxicity Deborah K. Lieu, PhD, UC Davis: The quest for pacemaking cardiomyocytes to engineer biopacemakers Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36336]

Can we discover new therapies for the heart with stem cells? From finding safer medication to preventing cardiac arrest, experts share the latest in the field of cardiac stem cell research. Moderated by Anthony DeMaria, MD, UC San Diego Pat Farrant: Patient Perspective Deepak Srivastava, MD, Gladstone Institutes: Cellular Reprogramming Approaches for Heart Disease Mark Mercola, PhD, Stanford University: Induced Pluripotent Stem Cell (iPSC)-derived Cardiomyocytes for Predicting and Removing Drug Cardiotoxicity Deborah K. Lieu, PhD, UC Davis: The quest for pacemaking cardiomyocytes to engineer biopacemakers Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36336]

Paul J. Wang: Welcome to the monthly podcast, On the Beat for Circulation: Arrhythmia and Electrophysiology. I'm Dr. Paul Wang, Editor-in-Chief, with some of the key highlights from this month's issue. In our first paper, Bruce Wilkoff and associates examine the impact of cardiac implantable electronic device [CIED] infections on mortality, quality of life, healthcare utilization, and cost in the U.S. Healthcare system. They found that the majority CIED infection was associated with increased all-cause mortality, 12-month risk-adjusted hazard ratio 3.41, P < 0.001. An effect that sustained beyond 12 months.   The quality of life was reduced, P = 0.004, and did not normalize for six months. Disruptions in CIED therapy were observed in 36% of infections for a median duration of 184 days. The authors reported that the mean hospital costs were $55,547.   In our next paper, Songwen Chen, Xiaofeng Lu and associates examine the ability to eliminate premature ventricular complexes [PVCs] originating from the proximal left anterior fascicle, safely from the right coronary sinus. The authors mapped the the right coronary sinus and left ventricle in 20 patients with left anterior fascicle PVCs. They found that the earliest activation site with Purkinje potential during both PVC and sinus rhythm was localized at proximal left anterior fascicle in eight patients, the proximal group, or non-proximal left anterior fascicle in 12 groups, the non-proximal group. The Purkinje potentials proceeded PVC-QRS at the earliest activation site in proximal group 32.6 milliseconds was significantly earlier than that in non-proximal group, 28.3 milliseconds P = 0.025. Similar difference in the Purkinje potentials proceeding sinus QRS at the earliest activation site was also observed between proximal and non-proximal group, 35.1 milliseconds versus 25.2 milliseconds, P < 0.001.   In proximal group, the distance between the earliest activation site to the left His-bundle into the right coronary sinus were shorter than that of the non-proximal group 12.3 millimeters versus 19.7, P = 0.002, and 3.9 millimeters versus 15.7 millimeters, P < 0.001, respectively. The authors found no difference in the distance between the right coronary sinus to proximal left anterior fascicle between the two groups. PVCs were successfully eliminated from the right coronary sinus in all proximal group, but at left ventricular earliest activation site for the non-proximal group, the radiofrequency application time, ablation time and procedure time of non-proximal group were longer than that proximal group.   Electrocardiographic analysis showed that when compared to non-proximal group, the PVCs proximal group had a narrower QRS duration, smaller S wave in leads one, V five,and V six; lower R waves in leads one, aVL, aVR, V one, V two, and V four and smaller q wave in leads three and aVF. The QRS duration difference [PVC-QRS and sinus rhythm QRS] < 15 milliseconds predicted the proximal left anterior fascicle origin with high sensitivity and specificity.   In our next paper, Benjamin Steinberg and associates examined the factors that are associated with large improvements in health-related quality of life in patients with atrial fibrillation. The authors assessed factors associated with a one-year increase in quality of life, measured by AFEQT of one standard deviation that is greater and equal to 18 points, three times clinically important difference among patients in the ORBIT-AF one registry. They found that 28% of patients had such a health-related quality improvement compared with patients not showing large health-related quality of life improvement. They were similar age, (median 73 versus 74 years of age), equally likely to be female, (44% versus 48%), but more likely to have newly diagnosed atrial fibrillation [AF] at baseline (18% versus 8%, P = 0.0004) prior antiarrhythmic drug use (52% versus 40%, P = 0.005), baseline antiarrhythmic drug use (34.8% versus 26.8%, P = 0.045), and more likely to undergo AF related procedures during follow-up (AF ablation 6.6% versus 2.0%, cardioversion 12.2% versus 5.9%). In multivariate analysis, a history of alcohol abuse has a ratio 2.4 and increased baseline diastolic blood pressure has a ratio 1.23 per 10 point increase and greater than 65 millimeters of mercury were associated with large improvements in health-related quality of life at one year. Whereas patients with prior stroke, chronic obstructive pulmonary disease and peripheral artery disease were less likely to improve.   In our next paper, Eiichi Watanabe and associates studied safety and resource consumption of exclusive remote follow-up in pacemaker patients for two years. Consecutive pacemaker patients committed to remote pacemaker management were randomized to either remote follow-up or conventional in-office follow-up at twice yearly intervals.   Remote follow-up patients were only seen if indicated by remote monitoring, all returned to hospital after two years. In 1,274 randomized patients (50.4% female, age 77 years), 558 remote follow-up or 550 conventional in office follow-up patients reached either the primary end point or 24 months follow-up. The primary end point, a composite of death, stroke, or cardiovascular events requiring surgery occurred in 10.9% and 11.8% respectively in the two groups (P = 0.0012) for non-inferiority. The median number of in-office follow-ups was 0.5 in the remote follow-up group and 2.01 in the conventional in-office follow-up per patient year (P < 0.001). Only 1.4% of remote follow-ups triggered an unscheduled in-office follow-up, and only 1.5% of scheduled in-office follow-ups were considered actionable.   In our next paper, Sarah Strand and associates use fetal magnetocardiography from the University of Wisconsin biomagnetism laboratory to study 39 fetuses with pathogenic variants in long QT syndrome, LQTS genes. 27 carried the family variant, 11 had de novo variants, and one was indeterminant. De novo variants, especially de novo SCN5A variants were strongly associated with a severe rhythm phenotype and perinatal death. Nine or 82% showed signature LQTS rhythms, six showed torsade de pointes, five were still born, and 9% died in infancy. Those that died exhibited novel fetus rythms, including AV block with 3:1 conduction ratio, QRS alternans in 2:1 AV block, long cycle length, torsade de pointes, and slow monomorphic ventricular tachycardia. Premature ventricular contractions were also strongly associated with torsade de pointes and perinatal death. Fetuses with familiar variants showed a lower incidence of signature LQTS rhythm, six out of 27 or 22%, including torsade de pointes, and 3 out of 27 or 11% all were live born. The authors concluded that the malignancy of de novo LQTS variants was remarkably high and demonstrate that these mutations are a significant cause of stillbirth.   In our next paper, Corina Schram-Serban and associates compare the severity of extensiveness of conduction disorders between obese patients and non-obese patients measured at high resolution scale. They studied 212 patients undergoing cardiac surgery (male:161, mean 63 years of age), who underwent epicardial mapping of the right atrium, Bachmann's bundle, and left atrium during sinus rhythm. Conduction delay [CD] was defined as interelectrode conduction time seven to 11 milliseconds and conduction block [CB] as conduction time ≥ 12 milliseconds. In obese patients, the overall incidence of conduction delay was 3.1% versus 2.6% (P = 0.002), conduction block 1.8% versus 1.2%, and continuous CDCB 2.6% versus 1.9% higher in the obese patients, conduction delay (P = 0.012) and continuous CDCB lines are longer. There were more conduction disorders at Bachman's bundle, and this area has a higher incidence of conduction delay 4.4% versus 3.3% (P = 0.002), conduction block 3.1% versus 1.6% (P < 0.001), continuous conduction block conduction delay 4.6% versus 2.7% and longer conduction delay or conduction delay conduction block lines. Severity of conduction block is also higher, particularly in the Bachmann bundle and pulmonary vein areas. In addition, obese patients have a higher incidence of early de novo postoperative atrial fibrillation. Body mass index and the overall amount of conduction block were independent predictors for the incidents of early postoperative atrial fibrillation.   In our next paper, Ricardo Cardona-Guarache and associates describe five patients with concealed, left-sided nodoventricular in four patients and nodofascicular in one patient accessory pathways. They proved the participation of accessory pathway in tachycardia by delivering His-synchronous premature ventricular complexes that either delayed the subsequent atrial electrogram or terminated the tachycardia, and by observing an increase in ventricular atrial interval coincident with left bundle branch block in two patients. The accessory pathways were not atrioventricular pathways because the septal ventricular atrial interval during tachycardia was less than 70 milliseconds in 3, 1 had spontaneous AV dissociation, and in 1 the atria were dissociated from the circuit with atrial overdrive pacing.   Entrainment from the right ventricle showed ventricular fusion in 4 out of 5 cases. A left-sided origin of accessory pathways was suspected after failed ablation of the right inferior extension of the AV node in 3 cases and by observing VA increase in left bundle branch block in 2 cases. The nodofascicular in 3 of the 4 nodoventricular accessory pathways were successfully ablated from within the proximal coronary sinus guided by recorded potentials at the roof of the coronary sinus, and nodoventricular accessory pathway was ablated via a transseptal approach near the coronary sinus os.   In our next paper, Pierre Qian and associates examined whether an open irrigated microwave catheter ablation can achieve deep myocardial lesions endocardially and epicardially through fat while acutely sparing nearby coronary arteries. Epicardial ablations via subxiphoid access in pigs were performed at 90 to 100 Watts at four minutes at sites near coronary arteries and produced mean lesion depth of 10 millimeters, width 18 millimeters, and length 29 millimeters through median epicardial fat thickness of 1.2 millimeters. Endocardial ablations at 180 Watts achieved depths of 10.7 millimeters, width of 16.6 millimeters, and length of 20 millimeters. Acute coronary occlusion or spasm was not observed at median separation distance of 2.7 millimeters.   In our next paper, Jad Ballout and associates examined 21 consecutive patients with cardiogenic shock and refractory ventricular arrhythmias undergoing bailout ablation due to inability to wean off of mechanical support. Mean age was 61 years, 86% were males, median left ventricular injection fraction 20%, 81% ischemic cardiomyopathy. The type of mechanical support in place prior to the procedure was intra-aortic balloon pump in 14 patients, Impella in 2, ECMO in 2, ECMO and intra-aortic balloon pump in 2, and ECMO and Impella in 1. In the cardio voltage maps with myocardial scar in 90% (19 patients), the clinical ventricular tachycardias VTs were inducible in 13% (62 patients), whereas 6 patients had PVC induced ventricular fibrillation, VT (29%), and VT could not be induced in 2 patients (9%). Activation mapping was possible in all 13 patients with inducible clinical VTs, substrate modification was performed in 15 patients with scar in 79%. After ablation and scar modification, the arrhythmia was noninducible in 19 patients (91%). Seventeen (81%) were eventually weaned off mechanical support successfully with the majority of patients being discharged home and surviving beyond one year. However, 6 (29%) died during the index admission with persistent cardiogenic shock.   In a research letter, Parveen Garg and associates examined the multi-ethnic study of atherosclerosis [MESA] incident atrial fibrillation a population with 50% African-American or Hispanic. After adjusting for age, race, ethnicity, sex education, income, clinic site, height, body, mass index, cigarette, smoking, diabetes, systolic and diastolic blood pressure, and hypertensive medications, physical activity, alcohol consumption, lipid parameter to lipid lowering therapy, the baseline lipoprotein A level greater or equal to 30 milligram per deciliter was inversely associated with developing atrial fibrillation compared those with lower levels (hazard ratio 0.84). However, the mechanism of this paradoxical association is unclear.   In another research letter, Yoshihide Takahashi and associates reported that 49 patients undergoing ablation of persistent atrial fibrillation had at least one focal site and rotational activation in 57%. Of these, 19 patients underwent a repeat ablation for recurrent atrial fibrillation. AF was mapped in 17 patients and 131 focal activation sites were ablated. There were 105 displayed focal activation sites during the de novo ablation and 89 focal activation sites during the repeat ablation. During the de novo ablation, rotation activation was observed in 19 sites. Of the 19 sites, 12 (63%) displayed rotational activity, also with the repeat ablation. The author suggested focal or rotational activation sites can be classified into two types, ones critical for AF recurrence and the ones that are bystander.   That's it for this month. We hope that you'll find the journal to be the go-to place for everyone interested in the field. See you next time.   This program is copyright American Heart Association, 2020.   Correction: In the study by Pierre Qian and associates, the epicardial ablations via subxiphoid access were performed in sheep, not pigs, as previously stated.

Asistanlık yıllarımdan bir nöbet. Kırklı yaşlarında bir kadın hasta 112 tarafından nöbet diye getirilmişti. Yakınlarından hastanın kasılma ve morarması olduğunu öğrendik, hasta bu kısmı hiç hatırlamıyordu ve özgeçmişinde bilinen başka bir hastalığı yoktu. Hastanın bilinci açık, GKS 15, nörolojik muayenesi doğaldı. Benim de aklıma ilk olarak nöbet geldi, hastanın tetkiklerini istedim, orderını verdim, bunlar yapılırken hasta tekrar nöbet geçirdi. Çok kısa sürmüştü ve postiktali olmamıştı. İkinci kez nöbeti olunca hastayı tomografiye gönderdik. Tabii öncesinde EKG çektik, çektiğimiz sırada hasta nöbet geçirmiyordu ve EKG o anki değerlendirmemle normaldi ve herhangi bir aritmi yok idi. Hasta BT’den döndüğünde ekip, hastanın çekim sırasında da nöbet geçirdiğini söyledi. BT’de akut patoloji yoktu. Mükerrer nöbetleri olunca hastayı monitorize ettik, nörolojiye haber verdik ve fenitoin yüklemeye başladık. Fenitoin devam ederken hasta VF'ye girdi ancak birkaç saniye sürmüştü ve defibrile etmeden hasta normal ritme geri döndü. Fenitoin infüzyonunu durdurduk, hastayı monitörize izlemeye devam ediyoruz, bu arada nöroloji de geldi. Hasta tekrar VF'ye girince tabiri caizse bizde jeton düştü. Hasta nöbet geçirmiyor VF’ye girip çıkıyordu. Zaten postiktal dönemi de yoktu. Dış merkeze koroner YBÜ’ye sevk edildi. Sonrasında aileye yapılan genetik taramada Na kanalopatisi saptandığını ve hasta ve çocuklarına ICD takıldığını öğrendik. Bu da bana ders olsundu. Aradan 8 yıl geçti, şimdi de belki bu yazı meslekte yeni arkadaşlarıma yol gösterici olur. Kalıtsal aritmi sendromları nadir görülüyor olmalarına rağmen, erken tanı ile ölüm riski ciddi oranda azaltılabileceğinden oldukça önemli bir başlıktır. Kırk yaş altında ani kardiyak ölüm insidansı yıllık 3/100.000’dir ve yapılan araştırmalar bu ölümlerin çoğuna, kalıtsal kalp hastalıklarının neden olduğunu göstermiştir. Bu vakaların %70’inde neden, primer aritmi sendromları, %30’unda ise aritmi riski oluşturan yapısal kalp hastalıklarıdır. En sık karşılaşılan primer aritmi sendromları​1​: Uzun QT sendromu (LQTS)Katekolaminerjik polimorfik ventriküler taşikardi (CPVT)Brugada sendromu (BrS)Daha nadirende,Kısa QT sendromu (SQTS)Erken repolarizasyon senromu (ERS)ve idiopatik ventriküler fibrilasyon (IVF)’ dur. Aritmi riski oluşturan yapısal kalp hastalıkları arasında ise​1​: Hipertrofik (Obstruktif) Kardiyomiyopati (HOCM, HCM)Dilate kardiyomiyopati (DCM)Ve Aritminojenik sağ ventrikül kardiyomiyopatisi/displazisi (ARVC/D) sayılabilir. Ani kardiyak ölüm dışında bu hastaların tipik başvuru şikayetleri çarpıntı, spontan geri dönen kısa bilinç kaybı (senkop) ve spesifik tetikleyicilerin uyardığı aritminojenik nöbetlerdir. LQTS ve CPVT’de senkop genellikle fiziksel efor, psikolojik stres veya saat alarmı gibi ani yüksek seslerden sonra olur. BrS’de ise aritmi genellikle uyku ve ateşlenme sırasında görülür. Hasta öyküsünde, genç aile bireylerinde açıklanamayan ani ölüm veya akrabalarında bilinmeyen nedene bağlı senkop ataklarından bahsediyorsa kalıtsal kardiyak aritmiler (KKA) akla gelmelidir. KKA için bir diğer risk faktörü, başka bir nedenle açıklanamayan EKG anomalileridir. Bu anomaliler: Uzamış QT intervaliStres EKG ‘de ventriküler ekstrasistollerPrekordiyal derivasyonlarda ST segment elevasyonuNegatif veya anormal T dalgaları olabilir. Bu hastalarda tanısal amaçlı ilk değerlendirme 12 derivasyonlu EKG, stres EKG ve EKO muayenesi ile yapılır. Klinik şüphe durumunda aşağıdaki algoritmaya göre genetik inceleme yapılması önerile bilinir. Hastalıkların çoğu otozomal dominanttır (OD), daha nadiren otozomal resesif (OR) kalıtım veya de nova mutasyonlar gözlenebilir. Beckmann BM, Pfeufer A, Kääb S. Inherited cardiac arrhythmias: diagnosis, treatment, and prevention. Dtsch Arztebl Int. 2011 Sep;108(37):623-33; quiz 634. doi: 10.3238/arztebl.2011.0623. ​1​ Ancak unutulmamalıdır ki, genetik testin NEGATİF çıkması, klinik şüphenin devamı halinde tanının tamamen dışlanmasını ...

Asistanlık yıllarımdan bir nöbet. Kırklı yaşlarında bir kadın hasta 112 tarafından nöbet diye getirilmişti. Yakınlarından hastanın kasılma ve morarması olduğunu öğrendik, hasta bu kısmı hiç hatırlamıyordu ve özgeçmişinde bilinen başka bir hastalığı yoktu. Hastanın bilinci açık, GKS 15, nörolojik muayenesi doğaldı. Benim de aklıma ilk olarak nöbet geldi, hastanın tetkiklerini istedim, orderını verdim, bunlar yapılırken hasta tekrar nöbet geçirdi. Çok kısa sürmüştü ve postiktali olmamıştı. İkinci kez nöbeti olunca hastayı tomografiye gönderdik. Tabii öncesinde EKG çektik, çektiğimiz sırada hasta nöbet geçirmiyordu ve EKG o anki değerlendirmemle normaldi ve herhangi bir aritmi yok idi. Hasta BT’den döndüğünde ekip, hastanın çekim sırasında da nöbet geçirdiğini söyledi. BT’de akut patoloji yoktu. Mükerrer nöbetleri olunca hastayı monitorize ettik, nörolojiye haber verdik ve fenitoin yüklemeye başladık. Fenitoin devam ederken hasta VF'ye girdi ancak birkaç saniye sürmüştü ve defibrile etmeden hasta normal ritme geri döndü. Fenitoin infüzyonunu durdurduk, hastayı monitörize izlemeye devam ediyoruz, bu arada nöroloji de geldi. Hasta tekrar VF'ye girince tabiri caizse bizde jeton düştü. Hasta nöbet geçirmiyor VF’ye girip çıkıyordu. Zaten postiktal dönemi de yoktu. Dış merkeze koroner YBÜ’ye sevk edildi. Sonrasında aileye yapılan genetik taramada Na kanalopatisi saptandığını ve hasta ve çocuklarına ICD takıldığını öğrendik. Bu da bana ders olsundu. Aradan 8 yıl geçti, şimdi de belki bu yazı meslekte yeni arkadaşlarıma yol gösterici olur. Kalıtsal aritmi sendromları nadir görülüyor olmalarına rağmen, erken tanı ile ölüm riski ciddi oranda azaltılabileceğinden oldukça önemli bir başlıktır. Kırk yaş altında ani kardiyak ölüm insidansı yıllık 3/100.000’dir ve yapılan araştırmalar bu ölümlerin çoğuna, kalıtsal kalp hastalıklarının neden olduğunu göstermiştir. Bu vakaların %70’inde neden, primer aritmi sendromları, %30’unda ise aritmi riski oluşturan yapısal kalp hastalıklarıdır. En sık karşılaşılan primer aritmi sendromları​1​: Uzun QT sendromu (LQTS)Katekolaminerjik polimorfik ventriküler taşikardi (CPVT)Brugada sendromu (BrS)Daha nadirende,Kısa QT sendromu (SQTS)Erken repolarizasyon senromu (ERS)ve idiopatik ventriküler fibrilasyon (IVF)’ dur. Aritmi riski oluşturan yapısal kalp hastalıkları arasında ise​1​: Hipertrofik (Obstruktif) Kardiyomiyopati (HOCM, HCM)Dilate kardiyomiyopati (DCM)Ve Aritminojenik sağ ventrikül kardiyomiyopatisi/displazisi (ARVC/D) sayılabilir. Ani kardiyak ölüm dışında bu hastaların tipik başvuru şikayetleri çarpıntı, spontan geri dönen kısa bilinç kaybı (senkop) ve spesifik tetikleyicilerin uyardığı aritminojenik nöbetlerdir. LQTS ve CPVT’de senkop genellikle fiziksel efor, psikolojik stres veya saat alarmı gibi ani yüksek seslerden sonra olur. BrS’de ise aritmi genellikle uyku ve ateşlenme sırasında görülür. Hasta öyküsünde, genç aile bireylerinde açıklanamayan ani ölüm veya akrabalarında bilinmeyen nedene bağlı senkop ataklarından bahsediyorsa kalıtsal kardiyak aritmiler (KKA) akla gelmelidir. KKA için bir diğer risk faktörü, başka bir nedenle açıklanamayan EKG anomalileridir. Bu anomaliler: Uzamış QT intervaliStres EKG ‘de ventriküler ekstrasistollerPrekordiyal derivasyonlarda ST segment elevasyonuNegatif veya anormal T dalgaları olabilir. Bu hastalarda tanısal amaçlı ilk değerlendirme 12 derivasyonlu EKG, stres EKG ve EKO muayenesi ile yapılır. Klinik şüphe durumunda aşağıdaki algoritmaya göre genetik inceleme yapılması önerile bilinir. Hastalıkların çoğu otozomal dominanttır (OD), daha nadiren otozomal resesif (OR) kalıtım veya de nova mutasyonlar gözlenebilir. Beckmann BM, Pfeufer A, Kääb S. Inherited cardiac arrhythmias: diagnosis, treatment, and prevention. Dtsch Arztebl Int. 2011 Sep;108(37):623-33; quiz 634. doi: 10.3238/arztebl.2011.0623. ​1​ Ancak unutulmamalıdır ki, genetik testin NEGATİF çıkması, klinik şüphenin devamı halinde tanının tamamen dışlanmasını ...

Can we discover new therapies for the heart with stem cells? From finding safer medication to preventing cardiac arrest, experts share the latest in the field of cardiac stem cell research. Moderated by Anthony DeMaria, MD, UC San Diego Pat Farrant: Patient Perspective Deepak Srivastava, MD, Gladstone Institutes: Cellular Reprogramming Approaches for Heart Disease Mark Mercola, PhD, Stanford University: Induced Pluripotent Stem Cell (iPSC)-derived Cardiomyocytes for Predicting and Removing Drug Cardiotoxicity Deborah K. Lieu, PhD, UC Davis: The quest for pacemaking cardiomyocytes to engineer biopacemakers Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36336]

Can we discover new therapies for the heart with stem cells? From finding safer medication to preventing cardiac arrest, experts share the latest in the field of cardiac stem cell research. Moderated by Anthony DeMaria, MD, UC San Diego Pat Farrant: Patient Perspective Deepak Srivastava, MD, Gladstone Institutes: Cellular Reprogramming Approaches for Heart Disease Mark Mercola, PhD, Stanford University: Induced Pluripotent Stem Cell (iPSC)-derived Cardiomyocytes for Predicting and Removing Drug Cardiotoxicity Deborah K. Lieu, PhD, UC Davis: The quest for pacemaking cardiomyocytes to engineer biopacemakers Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36336]

Can we discover new therapies for the heart with stem cells? From finding safer medication to preventing cardiac arrest, experts share the latest in the field of cardiac stem cell research. Moderated by Anthony DeMaria, MD, UC San Diego Pat Farrant: Patient Perspective Deepak Srivastava, MD, Gladstone Institutes: Cellular Reprogramming Approaches for Heart Disease Mark Mercola, PhD, Stanford University: Induced Pluripotent Stem Cell (iPSC)-derived Cardiomyocytes for Predicting and Removing Drug Cardiotoxicity Deborah K. Lieu, PhD, UC Davis: The quest for pacemaking cardiomyocytes to engineer biopacemakers Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36336]

Can we discover new therapies for the heart with stem cells? From finding safer medication to preventing cardiac arrest, experts share the latest in the field of cardiac stem cell research. Moderated by Anthony DeMaria, MD, UC San Diego Pat Farrant: Patient Perspective Deepak Srivastava, MD, Gladstone Institutes: Cellular Reprogramming Approaches for Heart Disease Mark Mercola, PhD, Stanford University: Induced Pluripotent Stem Cell (iPSC)-derived Cardiomyocytes for Predicting and Removing Drug Cardiotoxicity Deborah K. Lieu, PhD, UC Davis: The quest for pacemaking cardiomyocytes to engineer biopacemakers Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36336]

Can we discover new therapies for the heart with stem cells? From finding safer medication to preventing cardiac arrest, experts share the latest in the field of cardiac stem cell research. Moderated by Anthony DeMaria, MD, UC San Diego Pat Farrant: Patient Perspective Deepak Srivastava, MD, Gladstone Institutes: Cellular Reprogramming Approaches for Heart Disease Mark Mercola, PhD, Stanford University: Induced Pluripotent Stem Cell (iPSC)-derived Cardiomyocytes for Predicting and Removing Drug Cardiotoxicity Deborah K. Lieu, PhD, UC Davis: The quest for pacemaking cardiomyocytes to engineer biopacemakers Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36336]

Can we discover new therapies for the heart with stem cells? From finding safer medication to preventing cardiac arrest, experts share the latest in the field of cardiac stem cell research. Moderated by Anthony DeMaria, MD, UC San Diego Pat Farrant: Patient Perspective Deepak Srivastava, MD, Gladstone Institutes: Cellular Reprogramming Approaches for Heart Disease Mark Mercola, PhD, Stanford University: Induced Pluripotent Stem Cell (iPSC)-derived Cardiomyocytes for Predicting and Removing Drug Cardiotoxicity Deborah K. Lieu, PhD, UC Davis: The quest for pacemaking cardiomyocytes to engineer biopacemakers Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36336]

Can we discover new therapies for the heart with stem cells? From finding safer medication to preventing cardiac arrest, experts share the latest in the field of cardiac stem cell research. Moderated by Anthony DeMaria, MD, UC San Diego Pat Farrant: Patient Perspective Deepak Srivastava, MD, Gladstone Institutes: Cellular Reprogramming Approaches for Heart Disease Mark Mercola, PhD, Stanford University: Induced Pluripotent Stem Cell (iPSC)-derived Cardiomyocytes for Predicting and Removing Drug Cardiotoxicity Deborah K. Lieu, PhD, UC Davis: The quest for pacemaking cardiomyocytes to engineer biopacemakers Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36336]

Can we discover new therapies for the heart with stem cells? From finding safer medication to preventing cardiac arrest, experts share the latest in the field of cardiac stem cell research. Moderated by Anthony DeMaria, MD, UC San Diego Pat Farrant: Patient Perspective Deepak Srivastava, MD, Gladstone Institutes: Cellular Reprogramming Approaches for Heart Disease Mark Mercola, PhD, Stanford University: Induced Pluripotent Stem Cell (iPSC)-derived Cardiomyocytes for Predicting and Removing Drug Cardiotoxicity Deborah K. Lieu, PhD, UC Davis: The quest for pacemaking cardiomyocytes to engineer biopacemakers Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36336]

Mark Mercola, PhD Stanford University Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36334]

Mark Mercola, PhD Stanford University Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36334]

Mark Mercola, PhD Stanford University Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36334]

Mark Mercola, PhD Stanford University Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36334]

Mark Mercola, PhD Stanford University Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36334]

Mark Mercola, PhD Stanford University Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36334]

Mark Mercola, PhD Stanford University Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36334]

Mark Mercola, PhD Stanford University Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36334]

Mark Mercola, PhD Stanford University Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36334]

Mark Mercola, PhD Stanford University Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 36334]

This week's episode, co-branded with SADS.ORG, reviews a recent guideline paper by the Mayo Clinic on how to improve the safety of potential COVID-19 therapies such as azithromycin or hydroxychloroquine. These agents can both prolong the QT interval and enhance the risk for torsades making the development of a simple protocol to prevent possible life threatening cardiac side effects critical, particularly in an era before there is strong scientific evidence of efficacy of these agents when used for this indication. Dr. Ackerman shares with us his thoughts on a brief protocol he devised with his colleagues to identify 'at risk' individuals and shares his thoughts on how to thoughtfully consider the risks of these agents when considering their use for COVID-19 therapy. A timely episode with one of the world's greatest authorities on the QT interval in Professor Ackerman. Dr. Ackerman's algorithm is located at https://cdn.prod-carehubs.net/n1/802899ec472ea3d8/uploads/2020/03/2020-COVID-QTc-Algorithm-Internal-and-Media.pdf and the website he mentioned regarding a novel QT calculator for COVID patients is located at: https://www.covidqtc.com .

This week's episode, co-branded with SADS.ORG, reviews a recent guideline paper by the Mayo Clinic on how to improve the safety of potential COVID-19 therapies such as azithromycin or hydroxychloroquine. These agents can both prolong the QT interval and enhance the risk for torsades making the development of a simple protocol to prevent possible life threatening cardiac side effects critical, particularly in an era before there is strong scientific evidence of efficacy of these agents when used for this indication. Dr. Ackerman shares with us his thoughts on a brief protocol he devised with his colleagues to identify 'at risk' individuals and shares his thoughts on how to thoughtfully consider the risks of these agents when considering their use for COVID-19 therapy. A timely episode with one of the world's greatest authorities on the QT interval in Professor Ackerman. Dr. Ackerman's algorithm is located at https://cdn.prod-carehubs.net/n1/802899ec472ea3d8/uploads/2020/03/2020-COVID-QTc-Algorithm-Internal-and-Media.pdf and the website he mentioned regarding a novel QT calculator for COVID patients is located at: https://www.covidqtc.com .

Paul J. Wang: Welcome to the monthly podcast On the Beat for Circulation: Arrhythmia and Electrophysiology. I'm Dr Paul Wang, Editor-in-Chief with some of the key highlights from this month's issue. In our first paper, Jacob Koruth and Associates examine the ability to produce ablation lesions using pulse field ablation, which is tissue specific and non-thermal in swine compared to radio frequency ablation. All 46 targeted veins were successfully isolated on the first attempt in all cohorts. Pulmonary vein isolation durability was assessed in 28 veins, including the SVC. Durability was higher in the pulsed field ablation bipolar group, 18 out of 20 in the bipolar group, 10 out of 18 in the monopolar group, and 3 out of 6 in the radio frequency group. P = 0.002. Transmit morality rates were similar across groups with evidence of nerve damage only with radiofrequency. In our next paper, Vivek Reddy and Associates is part of the multicentered first-in-human study, RADIANCE, examine the ability of a novel compliant radio frequency balloon catheter with 10 irrigated flexible electrodes to simultaneously and independently deliver energy. At four sites, 39 patients with paroxysmal atrial fibrillation underwent pulmonary vein isolation using energy delivery simultaneously from all electrodes up to 30 seconds posteriorly, and 60 seconds anteriorly. 152 of 152 targeted pulmonary veins were isolated. 79.6% with a single application. Electrical reconnection occurred in only 7 out of 150 pulmonary veins or 4.7% upon adenosine isoproterenol challenge. Esophageal temperature was monitored in all patients. The esophagus was also mechanically deviated in ten patients. At three months, imaging revealed no pulmonary vein stenosis and early atrial recurrence occurred in only 10 out of 39 or 25.6% of patients. In our next paper Takeshi Kitamura and Associates examine the effect of substrate based ventricular tachycardia ablation targeting local abnormal ventricular activity on recurrent ventricular fibrillation events in patients with structural heart disease. In a retrospective two center study of a total of 686 patients with incident ventricular tachycardia ablation procedure targeting local abnormal ventricular activity, 21 patients, age 57 years left ventricular ejection fraction 30%, had both ventricular tachycardia and ventricular fibrillation. A total of 80 ventricular fibrillation events were recorded in the ICD logs, the six months preceding ablation. Complete and partial local abnormal ventricular activity elimination was achieved in 11 or 52%, in 10 or 58% of patients respectively. Catheter ablation was associated with a highly significant reduction in ventricular fibrillation recurrences. P less than 0.0001 which were limited to three or 14 patients at six months. The total number of ventricular events therefore, decreased from 80 to three with a median of 1.0 to 0.0 in the six months prior to and following ablation respectively. The reduction in ventricular fibrillation events was significantly greater in patients with catheter ablation compared to 21 match controls during a 6- month period preceding and following a baseline assessment. The authors concluded that substrate guided ventricular tachycardia ablation, targeting local abnormal ventricular activity, may be associated with a significant reduction in recurrent ventricular fibrillation, suggesting that ventricular tachycardia and ventricular fibrillation share overlapping arrhythmogenic substrate in patients with structural heart disease. In our next paper, Feng Hu and Associates examine the effect of right anterior ganglion aided plexi ablation on vagal response during circumferential pulmonary vein isolation. 80 patients with paroxysmal atrial fibrillation who underwent first time ablation were prospectively enrolled and randomly assigned to two groups. Group A (n = 40) circumferential pulmonary vein isolation starting with the right pulmonary veins at the right anterior ganglion plexi site. In group B (n = 40) circumferential pulmonary vein isolation starting with the left pulmonary veins first, and the last ablation site being the right anterior ganglionic plexi site. During circumferential pulmonary vein isolation, the positive vagal response was observed in only one patient in group A, in 25 patients in group B. P less than 0.001. A total of 21 patients with positive vagal response in group B needed temporary ventricular pacing during the procedure, while the only patient with positive vagal response in group A did not need temporary ventricular pacing, P less than 0.001. Compared with baseline basic cycle length, sinus node recovery time, and AV node Wenckebach pacing cycle length were decreased significantly after pulmonary vein isolation procedure in both groups, all P less than 0.05 and without differences between the two groups. In our next paper, Karl-Heinz Kuck and Associates reported the results of the randomized atrial fibrillation management and congestive heart failure with ablation, AMICA trial. Patients with persistent or long standing persistent atrial fibrillation and left ventricular ejection fraction ≤ 35%, were randomly allocated to catheter ablation of atrial fibrillation or best medical therapy. The primary study endpoint was the absolute increase in left ventricular ejection fraction from baseline at one year. Pulmonary vein isolation was the primary ablation approach. Best medical therapy comprised rate or rhythm control. All patients were discharged after index hospitalization with a cardioverter defibrillator or resynchronization therapy defibrillator implanted. This study was terminated early for futility of 140 patients, 65 years, 90% men available for endpoint analysis, 68 and 72 patients were assigned to ablation in best medical therapy respectively. At one year, left ventricular ejection fraction had increased in ablation patients by 8.8% and in medical therapy by 7.3%, P = 0.36. Sinus rhythm was recorded on 12-lead electrocardiograms at 1 year. In 61 of 83 ablation patients, or 73.5%, and 42 out of 82 best medical therapy patients or 50%. Device-recorded atrial fibrillation at one year, was 0% or maximally 50% of the time in 28 of 39 ablation patients, so 72% in 16 out of 36 best medical therapy patients or 44%. There were no differences in secondary endpoint outcomes of six-minute walk tests, quality of life or NT pro BNP between the ablation and best medical therapy patients. In our next paper, Dhanunjaya Lakkireddy and Associates examined the association between unrecognized inflammation and premature ventricular contraction. In a single-center prospective study, 107 patients with 5,000 or more PVCs per 24 hours, which were symptomatic, and no known ischemic heart disease, underwent combination of laboratory testing including FDG or 18F-fluorodeoxyglucose pet scan, cardiac magnetic resonance imaging, and biopsy. The mean age cohort was 57 years, 41% were males, a left ventricular ejection fraction was 47%. Positive pet scan was seen in 51%, and 51% had preserved left ventricular function. Based on clinical profile, FDG pet imaging, cardiac magnetic resonance imaging, and histological data, 58% received immunosuppressive therapy alone and 25% received immunosuppressive therapy and catheter ablation. Optimal response was seen in 67% over a mean follow-up of six months in patients with left ventricular systolic dysfunction, 37% showed a mean improvement in left ventricular ejection fraction of 13%. In our next paper, Clare Atzema and Associates examined the association of rapid (3 days), early (7 days), and basic (30 days), outpatient physician follow-up with short and long-term outcomes in atrial fibrillation patients discharged from an emergency department. In 163 emergency departments in Ontario, Canada with a diagnosis of atrial fibrillation, they use landmark analysis with propensity score matching. In the 10,657 patients with rapid follow-up care who are propensity score matched to a patient with follow-up between 4 and 7 days, the hazard of a return emergency visit was reduced by 11%. In the 17,234 patients with early follow-up who are matched to a patient with care between 8 and 30 days, the 1-year mortality was 11% lower, and 1-year hospitalization was 6% lower. Relative to no 30-day care, basic follow-up care was associated with an increased hazard ratio of 90-day hospitalization, but no longer was associated with mortality. The authors concluded that compared to follow-up care between 8 and 30 days, follow-up care within a week after discharge from an emergency department with atrial fibrillation, was associated with a reduction in death, in hospitalization at 1 year, in association not present with 30-day follow-up. In our next paper, James Freeman and Associates evaluate outcomes including death, myocardial infarction, stroke or systemic embolism, intracranial bleeding, major bleeding hospitalization in patients undergoing atrial fibrillation ablation compared with a propensity score match cohort of patients treated with anti-arrhythmic medications only in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) I and II registries. Among 21,595 patients, 6% underwent de novo atrial fibrillation ablation. The propensity score matched cohort included 1087 patients who underwent atrial fibrillation matched one-to-one with 1087 patients treated with an antiarrhythmic medication only. There were no significant differences in the risk of all-cause and cardiovascular death in most other major cardiovascular and neurologic events. Atrial fibrillation catheter ablation was associated with an increased risk of all cause hospitalization hazard ratio 1.24 particularly in the 3 months after the procedure. Among those who underwent atrial relation ablation with CHA2DS2 VAS score, 2 for men and 3 for women, 23% had oral anticoagulation discontinued after ablation. Among those with discontinue oral anticoagulation, the median time to discontinuation was 6.2 months. Thus, the authors found no difference in adjusted rates of cardiovascular and all-cause death, between patients treated with atrial fibrillation catheter ablation and antiarrhythmic medications only. In our next paper, Michael Liu and Associates examined R-from-T as a common mechanism of arrhythmia initiation in long QT syndrome. In their study, spontaneous initiation of polymorphic ventricular tachycardia was elicited by gradually ramping up ICa,L to simulate the early phase of sympathetic surge or changing the heart rate, reproducing the different genotype-dependent clinical electrocardiographic features in LQTS type 2 and 3, T-wave alternans was observed followed by premature ventricular complexes. Compensatory pauses occurred resulting in short-long sequences, as ICa,L increased further polymorphic ventricular tachycardia episodes occurred, always proceeded by short-long-short sequences. However, in LQTS type 1 once a PVC occurred, it almost immediately led to an episode of polymorphic ventricular tachycardia. Arrhythmias in LQT2 and 3 were bradycardia dependent, whereas LQT1 was not. In all 3 genotypes, PVCs always originated spontaneously from the steep repolarization gradient region and manifested on ECG as R-on-T. the authors called this mechanism R-on-T to distinguish it from the classic explanation of R-on-T arrhythmogenesis when an exogenous PVC coincidentally encounters a repolarization region. In R-from-T, the PVC and the T wave are causally related, where the steep repolarization gradients combine with enhanced ICa,L leading to the PVCs emerging from the T wave. Since enhanced ICa,L  was required for R-from-T to occur, suppressing window ICa,L  effectively prevented arrhythmias in all 3 genotypes. In our next paper, Dhani Dharmaprani and Associates hypothesized phase singularity formation and destruction in fibrillation could be modeled as a self-regenerating Poisson renewal processes, producing exponential distributions of inter event times governed by constant rate parameters defined by prevailing properties of each system. The authors studied 5 systems, human persistent atrial fibrillation in 20 cases, tachypaced atrial fibrillation in sheep in 5 cases, rat atrial fibrillation in 4 cases, and rat ventricular fibrillation in 11 cases, as well as computer simulated fibrillation. Phase singularity time to event data were fitted by exponential probability distribution functions computed using maximum entropy theory, and rates of phase singularity formation and destruction were determined. A systematic review is conducted to cross validate with sources from the literature. In all systems phase singularity lifetime and inter formation times were consistent with underlying Poisson renewal processes. The authors conclude that Poisson renewal theory provides an evolutionarily preserved universal framework to quantify formation and destruction of rotational events in cardiac fibrillation. In our issue, there was a very interesting special report on hypothermia outcomes after transvenous lead extraction complications requiring cardiothoracic surgery by Peter Hu and Associates. In addition, there is a very interesting review of atrial fibrillation mediated cardiomyopathy by Kevin Heist and Associates. That's it for this month. We hope that you'll find the journal to be the go-to place for everyone interested in the field. See you next time. This program is copyright American Heart Association 2019.  

Paul talks with cardiac arrest survivor Jasmine Wylie who is a patient advocate and online community leader. Jasmine talks about her cardiac arrest which was at the young age of 24 and was caused by Long QT Syndrome (LQTS). She also cover her recovery and subsequent work as a patient advocate where she helps others on the road to recovery via online communities and beyond. Presented by Paul Swindell and edited by Matt Nielson. Recorded October 2019 See acast.com/privacy for privacy and opt-out information.

This week's episode is co-branded with SADS.ORG and we review a paper on the clinical presentation of those who have conditions associated with sudden cardiac death. Are there questions about the patient and family history and physical examination signs that can improve the identification of those at risk before an event of cardiac arrest? We review this important question and others with Assistant Professor of Pediatrics at Washington University in St. Louis, Dr. Aarti Dalal. Referenced also in this discussion is the following webpage: https://www.sads.org/Library/School-Materials/Risk-Assessment#.XW25gy2ZOu4.DOI:10.1016/j.jpeds.2016.06.088

This week's episode is co-branded with SADS.ORG and we review a paper on the clinical presentation of those who have conditions associated with sudden cardiac death. Are there questions about the patient and family history and physical examination signs that can improve the identification of those at risk before an event of cardiac arrest? We review this important question and others with Assistant Professor of Pediatrics at Washington University in St. Louis, Dr. Aarti Dalal. Referenced also in this discussion is the following webpage: https://www.sads.org/Library/School-Materials/Risk-Assessment#.XW25gy2ZOu4.DOI:10.1016/j.jpeds.2016.06.088

This week's episode is our second 'co-branded' episode with the SADS Foundation (SADS.ORG) and we speak with the founder and director of Crediblemeds.org, Professor of Medicine Ray Woosley of the University of Arizona. Dr. Woosley speaks with us about how he started the first website dedicated to assessing the evidence for drugs' impact on the QT interval establishing a reliable and trusted website for clinicians and patients to visit to learn about possible drug interactions and their impact on LQTS and the QT interval in general. How was the site first conceived? What are the latest changes on the site? What are the plans for this work going forward? Is grapefruit juice really dangerous? Why does the site request that all have to sign up to access the site? Professor Woosley provides all the answers and more this week!

This week's episode is our second 'co-branded' episode with the SADS Foundation (SADS.ORG) and we speak with the founder and director of Crediblemeds.org, Professor of Medicine Ray Woosley of the University of Arizona. Dr. Woosley speaks with us about how he started the first website dedicated to assessing the evidence for drugs' impact on the QT interval establishing a reliable and trusted website for clinicians and patients to visit to learn about possible drug interactions and their impact on LQTS and the QT interval in general. How was the site first conceived? What are the latest changes on the site? What are the plans for this work going forward? Is grapefruit juice really dangerous? Why does the site request that all have to sign up to access the site? Professor Woosley provides all the answers and more this week!

This week we review the notion of sports participation in athletes who have ICD's. Is this a safe approach? How do the athletes fare? How do the devices stand up to sport? What are the subtleties of discussing this important topic with a family and how does shared decision making work in this process? We review this serious and complex topic with Dr. Rachel Lampert, Professor of Medicine at Yale University and Dr. Elizabeth Saarel, Professor of Pediatrics - The Cleveland Clinic. Both experts have much to share about their experience in this important work on how to potentially improve the quality of life for our ICD patients. doi: 10.1161/CIRCEP.118.006305

This week we review the notion of sports participation in athletes who have ICD's. Is this a safe approach? How do the athletes fare? How do the devices stand up to sport? What are the subtleties of discussing this important topic with a family and how does shared decision making work in this process? We review this serious and complex topic with Dr. Rachel Lampert, Professor of Medicine at Yale University and Dr. Elizabeth Saarel, Professor of Pediatrics - The Cleveland Clinic. Both experts have much to share about their experience in this important work on how to potentially improve the quality of life for our ICD patients. doi: 10.1161/CIRCEP.118.006305

Dr. Paul Wang:           Welcome to the monthly podcast On the Beat for Circulation Arrhythmia and Electrophysiology. I'm Dr Paul Wang, editor-in-chief, with some of the key highlights for this month's issue. We'll also hear from Dr. Suraj Kapa reporting on new research from the latest journal articles in the field.                                                 In our first article, Barry Maron associates report on the long term clinical course of hypertrophic cardiomyopathy patients following ICD therapy for ventricular arrhythmias. They studied a cohort of 486 high-risk hypertrophic cardiomyopathy patients with ICDs from eight international centers. Of these 486 patients over 6.4 years, 94 patients or 19% experienced appropriate ICD interventions, terminating VT or VF. Of the 94 patients receiving appropriate ICD therapy, 87 were asymptomatic or only mildly symptomatic at the time of appropriate ICD interventions. Of these 87 patients, 74 or 85% remained in classes one or two without significant change in clinical status of the subsequent 5.9 years up to 22 years. Among the 94 patients, there was one sudden death in three patients who died from non arrhythmic hypertrophic cardiomyopathy related processes. Post ICD intervention, freedom from hypertrophic cardiomyopathy, mortality was 100% at one year, 97% at five years, and 92% at 10 years, distinctly lower than the risk of ischemic or non ischemic cardiomyopathy in ICD trials.                                                 Hypertrophic cardiomyopathy patients with ICDs interventions reported the heightened anxiety and expectation of future shocks. However, they did not affect general psychological well-being or quality of life. The authors concluded that in hypertrophic cardiomyopathy, unlike ischemic heart disease, prevention of sudden death with ICD therapies unassociated with a significant increase in cardiovascular morbidity and mortality, nor transformation into heart failure deterioration, ICD therapy does not substantially impair overall psychological and physical well-being. In our next article, Abdulla Damluji and associates examined the cost of hospitalizations for cardiac arrest using the US nationwide inpatient sample from 2003 to 2012. Using the log transformation of inflation adjusted costs the authors examined 1,387,396 patients who were hospitalized after cardiac arrest. They had a mean age of 66 years. Inpatient procedures included coronary angiography in 15%, PCI in 7%, intra-aortic balloon pump in 4.4%, therapeutic hypothermia in 1.1%, and mechanical circulatory support in 0.1% of patients.                                                 Notably the rates of therapeutic hypothermia increased from 0 in 2003 to 2.7 in 2012, p less than 0.001. Both hospital charges inflation adjusted costs linear increased over time. In a multi-variant analysis predictors of inflation adjusted costs included large hospitals size, urban teaching hospital, and length of stay. Among co-morbidities, atrial fibrillation or fluid and electrolytes imbalance were the most common associated with cost. The authors found that during the period between 2003 and 2012 post cardiac arrest, hospitalizations had a steady rise and associated healthcare costs likely related to increase length of stay, medical procedures and systems of care.                                                 In our next paper, Peter Huntjens and associates examined intrinsic interventricular dyssynchrony as a predictor of human dynamic response to cardiac resynchronization. The authors use a cardiovascular computational model CircAdapt to characterize the isolated effect of intrinsic interventricular or intraventricular activation on resynchronization therapy response that is the change in LV dP/dt max. The simulated change in LV dP to dt max had a range of 1.3 to 26.5% increased considerably with increasing inter ventricular dyssynchrony. In contrast, the isolated effect of intra ventricular dyssynchrony was limited with the change in the LV dP/dt max range and the left ventricle from 12.3 to 18.3% in the right ventricle from 14 to 15.7%.                                                 Secondly, electrocardiographic imaging derived activation characteristics of 51 CRT candidates were used to create individual models of ventricular activation in CircAdapt. The model predicted change in LV dP/dt max was close to the actual value in left bundle branch block patients with 2.7% difference between measured and simulated when only intrinsic interventricular dyssynchrony was personalized. Among non left bundle branch block patients a change in LV dP/dt max was systematically over predicted by CircAdapt with a 9.2% difference between measured and simulated. Adding intra ventricular activation to the model did not improve the accuracy of response prediction. The authors found that computer revealed intrinsic interventricular dyssynchrony is the dominant component of the electrical substrate driving the response to CRT.                                                 In the next paper Kenji Kuroki and associates examined the use of voltage limit adjustment of substrate mapping and fast Fourier transform analysis of local ventricular bipolar electrograms during sinus rhythm to predict VT isthmuses. They performed these studies and nine post infarction patients who underwent catheter ablation for total of 13 monomorphic ventricular tachycardias. Relatively higher voltage areas on electroanatomical map or defined as high voltage channels, which were further classified as full or partial if the entire or more than 30% of the high voltage channel was detectable. 12 full high voltage channels were identified in seven of nine patients. Relatively higher fast Fourier transform areas were defined as high frequency channels, which were located on seven of 12 full high voltage channels. Five VT isthmuses or 71% were included in the seven full high voltage channels positive in high frequency channel positive sites.                                                 While no VT isthmuses were found in five full high voltage channel positive but high frequency channel negative sites, high frequency channels were identical to 9 out of 16 partial high voltage channels. Eight VT isthmuses or 89% were included in nine partial high voltage channel positive in high frequency channel positive sites, whereas no VTs isthmuses were found in the seven partial high voltage channel positive and high frequency channel negative sites.                                                 All high voltage channel positive in high-frequency channel positive sites predicted VT isthmus with a sensitivity of 100% and specificity of 80%. The authors concluded that based on this small series that combined use of voltage, limited adjustment and fast Fourier transform analysis may be useful method to detect VT isthmuses.                                                 In the next study, John Whitaker and associates examined the use of lesion index, LSI index, a proprietary algorithm combining contact force, radio-frequency application duration, and RF current. Cardiac CT was used to assess atrial tissue thickness. Ablation lines two to three per animal were created in the right atrium in seven mini pigs with point lesions using 25 watts of energy. Two weeks after the ablation, serial sections of targeted atrial tissue or examine histologically to identify gaps and transmural ablation. LSI guidelines had a lower incidence of histological gaps. Four gaps in the 69 catheter moved or 5.8% compared to ablation using LSI plus two millimeter lines in which there is seven gaps in 33 catheter moves or 21.2% and using LSI plus four millimeter lines in which there are 15 gaps in 23 moves or 65.2% p less than 0.0. The change in LSI was calculated retrospectively is a distance between two adjacent lesions above the mean LSI of the two lesions. Changing LSI values of 1.5 or less were associated with no gaps in transmural ablation.                                                 The authors concluded that in this mod of chronic atrial ablation delivery of uninterrupted transmural linear lesions may be facilitated using LSI to guide catheter movement. When change in LSI between adjacent legions is 1.5 millimeters or lower, no gaps in atrial linear lesions should be expected.                                                 In our next paper, Matthew Bennett and associate examined whether their response to antitachycardia pacing in patients with ICD could further discriminate ventricular from super ventricular arrhythmias in patients receiving ATP in the RAFT trial. The RAFT trial randomized 1,798 patients with New York Heart Association class two or three heart failure, left ventricular ejection fraction less than or equal to 30%, in QRS duration 120 millisecond or greater, to an ICD plus or a minus cardiac resynchronization. Beginning with 10,916 ATP attempts for 8,150 tachycardia episodes in 924 patients, the author's excluded tachycardias where ATP terminated the episode or were the specific etiology tachycardia was uncertain. In this study, they analyzed 3,676 ATP attempts delivered to 2,046 tachycardia episodes in 541 patients. The authors found that a shorter difference between the post pacing interval is PPI minus TCL, was more likely to be associated with VT than SVT, mean of 138.1 milliseconds for VT and 277.4 milliseconds for SVT p, less than 0.001. A PPI minus TCL value of less than or equal to 300 milliseconds had a sensitivity in 97.4% and a specificity of 28.3% for VT.                                                 The authors concluded that specifically the PPI minus TCL following antitachycardia pacing may help distinguish ventricular from supraventricular arrhythmias.                                                 In the next study, Shailee Shah and Amr Barakat and associates examined the outcomes after repeat AF ablation. The authors examined 137 patients out of a total of 10,378 patients undergoing Afib ablation who had had initial long-term success defined from recurrent arrhythmias for greater than 36 months off anti-arrhythmic drugs in subsequent underwent repeat ablation for recurrent atrial fibrillation. The median arrhythmia free period that define long-term success was 52 months. In redo-ablations reconnection of at least one of the pulmonary veins was found in 111 or 81% of patients. Additional non PV ablations were performed in 127 or 92.7% of patients. After a mean follow-up of 17 months, 103 patients or 75% were arrhythmia-free, 79 off anti-arrhythmics, and 24 on arrhythmics. The authors found that repeat ablations with re-isolation to the point of veins and modifying the atrial substrate had a good success rate.                                                 In the next article Qiongling Wang and associates hypothesized that genetic inhibition of CaMKII oxidation in a mouse model of Duchenne muscular dystrophy can alleviate abnormal calcium homeostasis thus preventing ventricular arrhythmias. The authors tested whether the selective loss of oxidation of the CaMKII effects ventricular arrhythmias in the mouse model of Duchenne muscular dystrophy. Genetic inhibition of ox-CaM kinase II by knocking replacement of the regulatory domain methionines with valines, which we'll call MMVV, prevented ventricular tachycardia in the mdx mice. Confocal calcium imaging of ventricular myocytes, isolated from the mdx MMVV mice revealed normalization of intra-calcium release events compared to myocytes from the mdx mice. Abnormal action potentials as assessed by optical mapping mdx were also alleviated by genetic inhibition of ox-CaMK II. Knockout of the NADPH oxidase regulatory sub-unit P 47 Fox normalized elevated ox-CaMK II, repaired intracellular calcium hemostasis and rescued inducible ventricular arrhythmias in the mdx mice. The authors concluded that inhibition of ROS or ox-CaMK II protects against pro-arrhythmic intracellular calcium handling, preventing ventricular arrhythmias in a mouse model of Duchenne muscular dystrophy.                                                 In the next article, Kyohei Marume and Teruo Noguchi and associates examined whether the combination of QRS duration of 120 milliseconds or greater in late gadolinium enhancement is a precise prognostic indicator for the primary endpoint of all cause death and a composite of sudden cardiac death or aborted sudden cardiac death in 531 patients with dilated cardiomyopathy. They also analyzed the association between the combination of late gadolinium enhancement and increased QRS duration in these end points among patients with a class one indication for implantable defibrillator. The author's divided study patients in three groups according to late gadolinium enhancement in QRS duration. Two negative indices that is late gadolinium enhancement negative and narrow QRS, one positive index with either late gadolinium enhancement positive or wide QRS or two positive indices late gadolinium positive and wide QRS and followed them for 3.8 years. Multiple variable Cox regression analysis identified to positive indices as significant predictors of all cause death. A hazard ratio of 4.29 p equals 0.026. Among the 317 patients with a class one indication for ICD, the five year event rate of sudden cardiac death or aborted sudden cardiac death was lowest in the two negative indices groups, 1.4%. With propensity score matching cohorts the two negative indices group had a significant lower event rate of sudden cardiac death or aborted sudden cardiac death than to two other groups hazard ratio 0.2, p equals 0.046.                                                 The authors concluded that the combination of late gadolinium enhancement in wide QRS provides additional prognostic stratification compared to late gadolinium enhancement status alone.                                                 In the next study, Matthew Sulkin and associates examined whether a novel local impedance measurement on an ablation catheter identifies catheter tissue coupling and is predictive of lesion formation. The author's first studied explanted hearts, 10 swine, and then in vivo 10 swine, using an investigational electro anatomical mapping system that measures impedance from an ablation catheter with mini electrodes incorporated into the distal electrode. Rhythmia and Intellanav, Boston Scientific.                                                 Explanted tissue was placed in a warmed 37 degree celsius saline bath mounted on a scale, and the local impedance was measured 15 millimeters away from the tissue to five millimeters of catheter tissue compression at multiple catheter angles. Lesions were created for 31 and 50 watts from 5 to 45 seconds for an N of 70. During in vivo valuation of the local impedance measurements of the myocardium 90 and blood pool 30 were guided by intracardiac ultrasound while operators were blinded to the local impedance data. Lesions were created with 31 and 50 watts for 45 seconds in the ventricle with an n of 72. The local impedance of myocardium, which was 119.7 ohms, was significantly greater than in blood pool 67.6 ohms the p of less than 0.01. Models that incorporate local impedance drop to predict lesion size had better performance that models incorporate force time integral r squared of 0.75 versus r squared of 0.54 and generator impedance drop r squared of 0.2 versus r squared of 0.58. Steam pops displayed a significantly higher starting local impedance and a larger change in local impedance compared to successful RF applications, p less than 0.01.                                                 The authors concluded that local impedance recorded for miniature electrodes provides a valuable measure of catheter tissue coupling and the change in local impedance is predictive of lesion formation during RF ablation.                                                 In the next paper, Boaz Avitall and associates found that the rising impedance recorded from a ring electrode placed two millimeters from the cryoballoon signifies ice formation covering the balloon surface and indicates ice expansion. The authors studied 12 canines in a total of 57 pulmonary veins, which were targeted for isolation. Two cryoapplications were delivered per vein with a minimum of 90 and a maximum 180 second duration. Cryoapplications was terminated upon reaching a 500 ohm change from baseline. Animals recovered 38 plus or minus six days post procedure, and the veins were assessed electrically for isolation. Heart tissue was histological examined. Extra cardiac structures were examined for damage. Pulmonary vein isolation was achieved in 100% of veins if the impedance reached 500 ohms in 90 to 180 seconds. When the final impedance was between 200 and 500 ohms within 180 seconds of freeze time, pulmonary vein isolation was achieved in 86.8%. For impedance of less than 200 ohms pulmonary vein isolation was achieved in 14%. No extra cardiac damage was recorded. The authors found that impedance rise of 500 ohms at less than 90 seconds with a freeze time of 90 seconds resulted in 100% pulmonary vein isolation.                                                 In our final papers Sally-Ann Clur and associates examined left ventricular isovolumetric relaxation time as the potential diagnostic marker for fetal Long QT Syndrome. Left ventricular isovolumetric contraction time, ejection time, left ventricular isovolumetric relaxation time, cycle length, and fetal heart rate were measured using pulse doppler wave forms in fetuses. Time intervals were expressed as percentage of cycle length, and the left ventricular myocardium performance index was calculated. Single measurements were stratified and compared between Long QT Syndrome fetuses and controls. Receiver operator curves were reformed for fetal heart rate in normalized left ventricular isovolumetric relaxation time. A linear mixed effect model including multiple measurements was used to analyze fetal heart rate, the left ventricular iso volume metric relaxation time, and the left ventricular myocardial performance index. There were 33 Long QT fetuses in 469 controls. In Long QT fetuses the left ventricular isovolumetric relaxation time was prolonged in all groups, p less than 0.001, as was the left ventricular isovolumetric relaxation time.                                                 The best cutoff to diagnose Long QT syndrome was the normalized left ventricular isovolumetric relaxation time greater than equal to 11.3 at less than or equal to 20 weeks, giving a sensitivity in 92% and a specificity of 70%. Simultaneous analysis of the normalized left ventricular isovolumetric relaxation time and fetal heart rate improved the sensitivity and specificity of Long QT Syndrome, AUC of 0.96. The normalized left ventricular isovolumetric relaxation time, the left ventricular myocardial performance index, and fetal heart rate trends differed significantly between Long QT Syndrome fetuses and controls throughout gestation.                                                 The authors concluded that left ventricular volumetric relaxation time is Prolonged QT fetuses. Findings of a prolonged normalize left ventricular isovolumetric relaxation time, and sinus bradycardia can improve the prenatal detection of fetal Long QT Syndrome.                                                 That's it for this month, but keep listening. Suraj Kapa will be surveying all journals for the latest topics of interest in our field. Remember to download the podcasts On the Beat. Take it away Suraj. Suraj Kapa:                          Thank you, Paul and welcome back to On the Beat were we will be summarizing hard-hitting articles across the entire electrophysiologic literature. Today we'll be starting within the realm of atrial fibrillation where we're review an article within the realm of anticoagulation and stroke prevention. Quon et al. published in last month's issue of JACC cardiac electrophysiology on anticoagulant use and risk of ischemic stroke and bleeding in patients with secondary atrial fibrillation. It is well known that use of anticoagulation in atrial fibrillation can reduce overall thromboembolic outcomes. However, its role in secondary atrial fibrillation is unclear. Thus, the authors sought to evaluate the effects anticoagulant use on stroke and bleeding risk. Amongst those where atrial fibrillation occurred in the setting of acute coronary syndrome, pulmonary disease, or sepsis. Amongst around 2300 patients evaluated retrospectively there was no evidence of a lower incidence of ischemic stroke among those treated with anticoagulants compared to those who are not.                                                 However, anticoagulation was associated with a higher risk of bleeding in those with new onset AF associated with acute pulmonary disease. The authors suggest as a result that there is unclear overall benefit for long-term anticoagulation in patients with presumed secondary atrial fibrillation. The difficulty in assessing this is how to define secondary atrial fibrillation. However, in many studies patients who developed in the setting of acute illness still had a high risk of developing quote unquote clinically significant AF in long-term follow-up. However, this was not necessarily absolute as many patients not necessarily develop AF that could be considered clinically significant. Thus, the clinical question that arises is: how long should we treat a patient with anticoagulation when they have presumed secondary atrial fibrillation. These data seem to suggest that there may be no net overall benefits. In other words, all-comers with secondary atrial fibrillation should not necessarily be forever treated with anti-coagulation. However, this slightly requires clinical trials to evaluate further.                                                 Next we delve into the realm of cardiac mapping and ablation where we view an article by Gaita et al. entitled 'Very long-term outcome following transcatheter ablation of atrial fibrillation. Are results maintained after 10 years of follow-up?', published in Europace last month. While pulmonary vein isolation is a widely accepted approach for treatment of atrial fibrillation, most reported studies review outcomes in terms of freedom of AF over a relatively short time period, generally two to five years. However longer term follow up is inconsistently reported. Gaita et al. sought to review 10 year outcomes amongst 255 patients undergoing ablation in a single center. They noted 52% remainder arrhythmia-free amongst a mixed cohort of both paroxysmal and persistent patients while 10% progressed to permanent atrial fiBrillation. They found that absence of increases in blood pressure, BMI, and fasting glucose was protective against an arrhythmia recurrence.                                                 These findings suggest that in a relatively small cohort of patients limited to a single center that even long-term outcomes after pulmonary vein isolation are generally quite good, exceeding 50%. However, future freedom from atrial fibrillation is heavily tied to control of other risk factors. In other words, if a patient is going to have poor control of diabetes, blood pressure, or gain weight, the benefit of their pulmonary vein isolation over long-term follow-up is likely less. These data thus highlight both the potential long-term benefit of PVI, but also the importance of counseling patients regarding the need for continued management and control of future and existing risk factors.                                                 Staying within the realm of atrial fibrillation we next review an article by Weng et al. entitled 'Genetic Predisposition, Clinical Risk Factor Burden, and Lifetime Risk of Atrial Fibrillation' published in last month's issue of circulation. The probability of detecting atrial fibrillation in patients based on clinical factors and genetic risk is unknown. Weng et al. sought to clarify whether a combination of clinical and polygenic risk scores could be used to predict risk of developing atrial fibrillation over long-term followup in the Framingham Heart Study. Amongst 4,600 individuals, 580 developed incident atrial fibrillation and had an overall lifetime risk of developing atrial fibrillation of 37%. Those are the lowest risk tertile based on clinical risk factor burden and genetic predisposition had a lifetime risk of 22% versus 48% in the highest. Furthermore, a lower clinical risk factor burden was associated with delayed atrial fibrillation onset. In order to identify patients with atrial fibrillation, before negative sequelae such as stroke occur, patient and physician understanding of risk and monitoring needs is necessary. The fact is that it will be great to identify every single patient who has atrial fibrillation before they have a negative sequela of that atrial fibrillation such as ischemic stroke.                                                 However, performing continuous monitoring of all patients with potential negative sequelae of atrial fibrillation is extraordinarily difficult. The reason is it's excessively costly. We cannot monitor the entire population irrespective of whatever the risk factors are. However, if we're able to identify the highest risk cohorts early on before the atrial fibrillation onsets, this may offer opportunities for use of newer cheaper monitors. The work by Weng et al. suggests one such possible approach combines clinical and polygenic risk scores. Actionability of these data, however, remains to be seen and further validation other cohorts is necessary to clarify generalized ability.                                                 The next article we review is published in last month's issue of the Journal of American College of Cardiology by Lopes at al. entitled 'Digoxin and Mortality in Patients With Atrial Fibrillation. Lopes et al. sought to evaluate the impact of the Digoxin on mortality in patients with atrial fibrillation and the association with the Digoxin serum concentration and heart failure status. They value this association in over 17,000 patients. At baseline 32% were receiving Digoxin. Baseline Digoxin use did not associate with risk of death, but even in these patients a serum concentration of greater than 1.2 nanograms per milliliter was associated with a 56% increase in mortality risk. For each .5 nanogram per milliliter increase in oxygen concentration the hazard ratio increased by 19% for overall mortality. This was irrespective of heart failure status. Furthermore, in patients who are newly started in Digoxin over the follow-up period, the risk and death and sudden death was higher. These data suggests a significant risk associated with Digoxin use for management of atrial fibrillation irrespective of heart failure status. Furthermore, serum valleys above 1.2 require close consideration of dose de-escalation. Whether there is any optimal dose, however, from the study is unclear. These data amongst a host of prior data strongly suggest again strategic use of Digoxin  principally for the management of atrial fibrillation.                                                 Moving on within the realm of atrial fibrillation, we review an article published in last month's issue of Circulation Research by Yan et al. entitled Stress Signaling JNK2 Crosstalk with CaMKII Underlies Enhanced Atrial Arrhythmogenesis. In this more acellular based study the mechanism underlying atrial arrhythmogenesis associated with aging was evaluated. Yan et al. sought to figure out whether the stress response JNK in calcium mediated arrhythmias might contribute to atrial arrhythmogenesis in aged transgenic mouse models. They demonstrated significant increased activity of JNK2 and aging atria, those furthermore associated with rhythmic remodeling. This association was mediated through CaMKII and ryanodine receptor channel function, with activation of the former leading to increased calcium leak mediated by the ladder. This in turn related to increase atrial fibrillation likelihood. Identifying novel targets for atrial fibrillation therapy is critical. Given atrial fibrillation is a complex disease process related to a multitude of risk factors it can be assumed that the contribution of any single factor may be mediated through distinct mechanisms.                                                 Aging in particular as well regarded, but considered to be non-modifiable risk factor for atrial fibrillation. Identifying genes or pathways, the immediate aging associated fibrillation, may take the risk of aging as no longer a non-modifiable thing. The finding of the significance of JNK2 and associate downstream effects with AF risks and aging hearts may hold potential in offering unique therapeutic targets.                                                 Finally, within the realm of atrial fibrillation, we're viewing article by Chen et al. in last month's issue of the Journal of the American Heart Association entitled Association of Atrial Fibrillation With Cognitive Decline and Dementia Over 20 Years: The ARIC-NCS Study. Multiple studies have suggested a significant association between atrial fibrillation risk of dementia. However, these studies have limited time follow-up and were often done and predominantly white patients. Thus, the authors sought to use the data from ARIC, the Atherosclerosis Risk in Communities Neurocognitive Study, to assess the risk of cognitive decline associated with atrial fibrillation. Amongst over 12,000 participants, a quarter of whom are black and half of whom are white, they noted 2100 patients developed atrial fibrillation and 1,150 develop dementia over a 20 year follow up period.                                                 There was a significantly greater risk of cognitive decline amongst those who developed atrial fibrillation. In turn incident atrial fibrillation for the follow-up period was associated with a higher risk of dementia even after adjusting for other clinical and cardiovascular risk factors such as incidents that ischemic stroke. These data further strengthened prior evidence of a direct link between atrial fibrillation and risk of cognitive decline and dementia. Understanding this long-term risk raises the need to additionally identify approaches to prevent this occurrence, which in turn is dependent on understanding the underlying mechanisms. The finding that the risk of cognitive decline dementias independent of ischemic stroke events raises concern that either subclinical micro-embolic events or other factors may be playing a role in this risk and in turn raises question as to how best to prevent them. Until better understood, however, the question of whether the association is causal remains to be seen.                                                 Changing gears yet again, we now delve into the realm of ICDs, pacemakers and CRT. Published in last month, issue of Heart Rhythm Tarakji et al. published a paper entitled 'Unrecognized venous injuries after cardiac implantable electronic device transvenous lead extraction.' Overall risk of transvenous lead extraction includes that of potentially fatal venous laceration. The authors sought to evaluate the incidence of venous injury that may be unrecognized based on microscopic study of extracted leads. Amongst 861 leads obtained from 461 patients they noted 80 leads or almost 9%. Amongst 15% of patients showed segments vein on the lead body, most of which were transmural including the tissue layer. However, in terms of clinical significance, only 1% had need for emergent surgical intervention for clinically significant venous laceration. Risk factors for having the entire vein on the lead included age of lead, ICD leads, and the use of the laser sheath.                                                 These findings suggest that there may be a high incidence of subclinical venous injury after lead extraction though rarely resulting clinically apparent sequelae. As would be expected, venous injury, including transmural removal of portions of the vein traversed by the lead, was more common amongst older leads, which generally more often require laser sheets and ICD leads. The question is however, whether this carries any direct clinical implications. One they may be considered is the potential additive risk of an advancing new lead through the same venous channel, particularly in the setting of potential transmural venous injury that already exists.                                                 Next in last month's issue of Heart Rhythm we review an article by Sharma at al. entitled 'Permanent His-bundle pacing as an alternative to biventricular pacing for cardiac resynchronization therapy: A multicenter experience.' The use of resynchronization therapy for treatment of patients with heart failure and wide QRS has been shown to offer morbidity and mortality benefits. However, many patients maybe non-responders, and recent studies on His bundle pacing of suggested potential clinical benefits. His bundle pacing essentially only requires one pacing catheter attached within the region of the His bundle Sharma et al. sought to evaluate the safety and success rates of His bundle pacing for patients who have either failed standard resynchronization therapy or in whom most tried as a primary intervention. They noted His bundle pacing was successful in 90% of patients with reasonable myocardial and His bundle capture thresholds. Patients in both groups exhibits significant narrowing of QRS morphology and improvement in left ventricular ejection fraction from a mean of 30 to 43%. However, a total of seven patients had lead related complications.                                                 These database on a retrospective analysis of two types of patients, those failing standard biventricular therapy, and those on whom his bundle pacing was attempted as a primary modality suggest overall safety and efficacy in a handful of experienced centers. The promise of His bundle pacing is that a may allow for more effective resynchronization than standard approaches. The high rate of success suggests that His bundle pacing maybe both safe and reasonable to pursue. However randomized trials across more centers are needed to fully prove its benefit, particularly as a primary modality of treatments.                                                 Next we review ICDs and chronic kidney disease. In last month's issue of JAMA cardiology by Bansal at al. entitled 'Long-term Outcomes Associated With Implantable Cardioverter Defibrillator in Adults With Chronic Kidney Disease.' While the benefit of ICDs in patients with low EF is widely recognized, modifying factors that may increase risk of death are not as well defined. These include things like advanced age and chronic kidney disease. Bansal et al. sought to evaluate long-term outcomes and ICD therapy in patients with chronic kidney disease. In retrospective study of almost 5,900 ambulatory patients amongst whom 1550 had an ICD, they found no difference in all cause mortality. However, ICD placement was associated with an increased risk of subsequent hospitalization due to heart failure or any cause hospitalization.                                                 In light of recent studies such as DANISH the robust sense of ICD benefit is being questioned. One of the thoughts for the absence of similar benefit to prior studies lies in the improving care of ambulatory heart failure patients. In patients with chronic kidney disease several questions rises to the risk with ICD, including infectious risk in dialysis patients and the concomitant mortality risk with renal dysfunction. The author suggested in retrospective study, no incremental benefit of ICDs in patients with chronic kidney disease and perhaps some element of added risk is related to hospitalization. However, this study has several limitations. It is retrospective and many patients received ICDs may have been perceived to be sicker in some way. Thus care must be taken in interpretation, but consideration of randomized studies to adjudicate benefit are likely necessary.                                                 Finally, within the realm of devices, we reviewed an article by Tayal et al. entitled "Cardiac Resynchronization Therapy in Patients With Heart Failure and Narrow QRS Complexes.' publishing the Journal of American College of Cardiology last month. Several parameters have been stressed to identify benefit of resynchronization therapy in patients with wide QRS include cross correlation analysis with tissue doppler imaging. However, many patients may have evidence in mechanical dyssynchrony even in the absence of an apparent wide QRS thus Tayal et al. sought to evaluate the benefit of resynchronization therapy amongst 807 patients with heart failure and a narrow QRS mean criteria in a randomized study. Of the 807 46% had delayed mechanical activation. Those without delay mechanical activation had underwent we standardization therapy and were associated with worse overall outcomes likely due to new delayed mechanical activation potentially related to CRT pacing. These data support the absence of a role for resynchronization therapy in patients with a narrow QRS. This is expected as resynchronization therapy likely offers the most benefit in patients with mechanical dyssynchrony that results from electrical dyssynchrony.                                                 Since by its very nature resynchronization therapy relies on non physiologic cardiac pacing thus compared to normal cardiac activation the nature of resynchronization pacing is desynchronization. These data support the absence of a role for resynchronization therapy in patients with heart failure and narrow QRS complexes.                                                 Moving on to cellular electrophysiology we review an article by Kozasa et al. published in last month's issue of Journal of Physiology entitled 'HCN4 pacemaker channels attenuate the parasympathetic response and stabilize the spontaneous firing of the sinoatrial node.' Heart rate is controlled by an interplay between sympathetic and parasympathetic components. In turn HCN4 abnormalities have been implicated in congenital sick sinus syndrome. The authors sought to clarify the contribution of HCN4 to sinus node autonomic regulation. They created a novel gain-of-function mouse where the HCN4 activity could be modulating from zero to three times normal. They then evaluated ambulatory heart-rate variability and responsive heart rate to vagus nerve stimulation. They found HCN4 over-expression did not increase heart rate, but attenuated heart-rate variability. It also attenuated bradycardic response to vagus nerve stimulation. Knockdown of HCN4 in turn lead to sinus arrhythmia and enhanced parasympathetic response. These data suggest HCN4 attenuates sinus node response to vagal stimuli thus stabilizing spontaneous firing of the node. The clinical application of this remain to be seen but are maybe important in that they highlight a mechanism for a heretofore poorly understood mechanism for how exactly HCN4 abnormalities may lead to sick sinus syndrome.                                                 Within the realm of ventricular arrhythmias we highlighted a number of articles published this past month. The first article we review was published in last month's issue of JACC clinical electrophysiology, entitled characterization of the electrode atomic substrate and cardiac sarcoidosis: correlation with imaging findings of scarring inflammation published by [inaudible 00:41:40] et al. In patients with cardiac sarcoidosis one of the questions is how to define the electronic atomic substrate, particularly before we entered the electrophysiology laboratory. Both active inflammation and replacement fibrosis maybe be seen in patients. The authors evaluated in 42 patients with cardiac sarcoidosis, the association between an abnormal electrograms and cardiac imaging findings including PET and Computed Tomography, as well as Cardiac MRI. They noted that amongst these 40 patients, a total of 21,000 electrograms were obtained, and a total of 19% of these were classified as abnormal. Most of the abnormalities occurred in the basal paravalvular segments and intraventricular septum. They further noted that many of these abnormalities in terms of electrograms were located outside the low voltage areas, particularly as it relates to fractionation. In about 90% of patients they notice late gadolinium enhancements and they noted abnormal FDG uptakes suggesting active inflammation in about 48%.                                                 However, it should be noted that only 29 of the 42 patients underwent cardiac imaging. Segments with abnormal electrograms tended to have more late gadolinium enhancement evidence scar transmurality, and also they noted that the association of abnormal PET scan did not necessarily occur with abnormal electrograms. Thus, they concluded that in patients with cardiac sarcoidosis and ventricular tachycardia pre-procedural imaging with cardiac MRI could be useful in detecting electroanatomic map abnormalities that may in turn be potential targets for substrate ablation. However, they were more likely associated with more scar transmurality and lower degrees of inflammation on PET scanning. These data are important in that they highlight potential non-invasive means by which to understand where substrate might occur in patients with the cardiac sarcoidosis. It is well recognized that cardiac sarcoidosis is associated with increased risk of ventricular arrhythmias. These risks have increased ventricular arrhythmias, might be targetable with ablation. Newer therapies might even offer non invasive means by which to perform ablation in patients best. Thus if we could identify non based on mechanisms of identifying the substrate, this will be even more critical.                                                 The critical findings of this particular paper lie in noting that most of the abnormalities still is in intra ventricular sePtum in basal segments, and also that it is MRI in late gadolinium enhancement and associates more with the abnormal electrograms. Interestingly, the absence of inflammation correlating with the presence of more abnormal electrograms suggests that it is not so much the act of inflammation as being reflected in the endocardial map, but the existence of scar.                                                 Next, again within JACC clinical electrophysiology we review an article by Porta-Sánchez et al. entitled 'Multicenter Study of Ischemic Ventricular Tachycardia Ablation With Decrement Evoked Potential Mapping With Extra Stimulus.' The authors sought to conduct a multicenter study of decrement evoked potential base functional tech ventricular tachycardia substrate modification to see if such mechanistic and physiologic strategies could result in reduction in VT burden. It is noted that really only a fraction of the myocardium in what we presume to be substrate based on the presence of low voltage areas are actually involved in the initiation and perpetuation of VT. Thus if we can identify the critical areas within the presumed substrate for ablation, this would be even a better way of potentially honing in on our targets. They included 20 consecutive patients with ischemic cardiomyopathy. During substrate mapping fractionated late potentials were targeted and an extra stimulus was provided to determine which display decrements. All patients underwent DEEP focus ablation with elimination being correlated with VT non-inducibility after radio-frequency ablation. Patients were predominantly male, and they noted that the specificity of these decrement evoked potentials to detect the cardiac isthmus for VT was better than that of using late potentials alone. They noted 15 of 20 patients were free of any VT after ablation of these targets over six months of follow-up, and there was a strong reduction in VT burden compared to six months pre ablation.                                                 They concluded that detriment evoked potential based strategies towards ablation for ventricular tachycardia might identify the functional substrate and those areas most critical to ablation. They in turn regarded that by its physiologic nature it offers greater access to folks to ablation therapies.                                                 This publication is important in that it highlights another means by which we can better hone in on the most critical regions for substrate evaluation in patients with ventricular tachycardia. The fact is more extensive ablation is not necessarily better and might result in increased risk of harm if we think about the potential effects of longer ablations or more ablation lesions. Thus if we could identify ways of only targeting those areas that are most critical to the VT circuits, we could perhaps short and ablation procedural time, allow for novel ways of approaching targeted ablation with limited amounts of ablation performed, or perhaps even improve overall VT outcomes by knowing the areas that are most critical to ensure adequate ablation therapy provided. However, we need to understand that this is still a limited number of patients evaluated in a non randomized manner. Thus whether or not more extensive ablation performed might have been better is as of yet unclear                                                 Staying within the realm of ventricular tachycardia we review an article published in last month's issue of Heart Rhythm by Winterfield et al. entitled the 'Impact of ventricular tachycardia ablation on healthcare utilization.' Catheter ablation of atrial tachycardia has been well accepted to reduce recurrent shocks in patients with ICDs. However, this is a potentially costly procedure, and thus effect on overall long-term health care utilization remains to be seen. The authors sought to evaluate in a large scale real world retrospective study the effect of VT ablation on overall medical expenditures in healthcare utilization. A total 523 patients met study inclusion criteria from the market scan database. After VT ablation median annual cardiac rhythm related medical expenditures actually decreased by over $5,000. Moreover the percentage of patients with at least one cardiac rhythm related hospitalization an ER visit decreased from 53 and 41% before ablation respectively, to 28 and 26% after ablation. Similar changes we're seeing in number of all cause hospitalizations and ER visits. During the year before VT ablation interestingly there was an increasing rate of healthcare resource utilization, but a drastic slowing after ablation.                                                 These data suggests that catheter ablation may lead to reduced hospitalization in overall healthcare utilization. The importance of these findings lies in understanding why we do the things we do. We can provide a number of therapies to patients, but we seek two different effects. One is the individual effect of improving their particular health. The second thing is trying to avoid increasing healthcare expenditures on a population level and making sure resources are utilized. If we can reduce recurrent hospitalizations and overall healthcare expenditure in patients by providing a therapy in addition to provide individual benefit, this is the optimal situation. These data suggests that VT ablation might provide such a benefits, that in fact it reduces overall healthcare utilization while improving overall outcomes.                                                 Next and finally within the realm of ventricular arrhythmias, we review more on the basic side the role of Titin cardiomyopathy leads to altered mitochondrial energetics, increased fibrosis and long-term life-threatening arrhythmias, published by Verdonschot et al. in last month's issue of European Heart Journal. It is known now that truncating Titin variants might be the most prevalent genetic cause of dilated cardiomyopathy. Thus, the authors sought to study clinical parameters and long term outcomes related to Titin abnormalities in dilated cardiomyopathy. They reviewed 303 consecutive and extensively phenotype dilated cardiomyopathy patients who underwent cardiac imaging, Holter monitoring, and endomyocardial biopsy and in turn also underwent DNA sequencing of 47 cardiomyopathy associated genes. 13% of these patients had Titin abnormalities. Over long-term followup they noted that these patients had increased ventricular arrhythmias compared to other types of dilated cardiomyopathy, but interestingly, they had similar survival rates. Arrhythmias in those Titin abnormal patients were most prominent in those who were subjected to an additional environmental trigger, including viral infection, cardiac inflammation, other systemic disease or toxic exposure. They also noted the cardiac mass was relatively reduced in titan admirable patients.                                                 They felt that all components of the mitochondrial electron transport chain we're simply up-regulated in Titin abnormal patients during RNA sequencing and interstitial fibrosis was also augmented. As a result, they concluded that Titin variant associated dilated cardiomyopathy was associated with an increased risk of ventricular arrhythmias, and also with more interstitial fibrosis. For a long time we have reviewed all non ischemic cardiomyopathy as essentially equal. However, more recent data has suggested that we can actually hone in on the cause. In turn, if we hone in on the cause, we might be able to understand the effects of specific therapies for ventricular arrhythmias based on that underlying cause. Patchy fibrosis might not be as amenable, for example, to ablation as discreet substrate that we might see in infarct related VT. Understanding the relative benefit in very specific types of myopathies might hold benefit in understanding how to, one, risk stratify these patients, and two, understand what type of therapy, whether pharmacologic or ablative, might result in greatest benefit to the patients.                                                 Changing gears entirely now to the role of genetics, we review multiple articles in various genetic syndromes published this past month. First, we reviewed an article by Providência et al. published in the last month's issue of heart entitled 'Impact of QTc formulae in the prevalence of short corrected QT interval and impact on probability and diagnosis of short QT syndrome.' The authors sought to assess the overall prevalence of short corrected QT intervals and the impact on diagnosis of short QT syndrome using different methods for correcting the QT interval. In this observational study they reviewed the sudden cardiac death screening of risk factors cohorts. They then applied multiple different correction formulae to the ECGs. They noted that the prevalence of individuals with the QTc less than 330 and 320 was extremely low, namely less than .07 and .02% respectively. They were also more frequently identified using the Framingham correction. The different QTc correction formulae could lead to a shift of anywhere from 5 to 10% of individuals in the cohort overall.                                                 They further noted, that based on consensus criteria, instead of 12 individuals diagnosed with short gut syndrome using the Bazett equation, a different number of individuals would have met diagnostic criteria with other formulae, 11 using Fridericia, 9 with Hodges, and 16 using the Framingham equation. Thus, they noted that overall the prevalence of short QT syndrome exceedingly low and an apparently healthy adult population. However, reclassification as meeting criteria might be heavily dependent on which QT correction formula is used. The importance of these findings is that not all QTs are created equal.                                                 Depending on how you compute the QT interval in which formula to use may affect how you actually risk characterize a patient. Unfortunately, these data do not necessarily tell us which is the right formula, but this highlights that it might be relevant to in the future evaluate the role of different formulae and identifying which is the most necessary to classify a patient.                                                 Moving on to an article published in last month's issue of the journal of clinical investigation by Chai et al. we review an article entitled 'Physiological genomics identifies genetic modifiers of Long QT Syndrome type 2 severity.' Congenital Long QT Syndrome is a very well recognized, inherited channelopathy associated life-threatening arrhythmias. LQTS type 2 is specifically caused by mutations in casein to encoding the potassium channel hERG. However, even with the mutation not all patients exhibit the same phenotype. Namely some patients are more at risk of life threatening arrhythmias in spite of having the same mutation as others who do not exhibit the same severity phenotype. The authors sought to evaluate whether specific modifiable factors within the remaining genetic code might be modifying the existing mutation. Thus, they sought to identify contributors to variable expressivity in an LQT 2 family by using induced pluripotent stem cell derived cardiomyocytes and whole exome sequencing in a synergistic manner.                                                 They found that patients with severely effected LQT 2 displayed prolonged action potentials compare to sales from mildly effected first-degree relatives. Furthermore, stem cells derived from patients were different in terms of how much L-type calcium current they exhibited. They noted that whole exome sequencing identified variants of KCNK17 and the GTP-binding protein REM2 in those patients with more severe phenotypes in whom greater L-type calcium current was seen. This suggests that abnormalities or even polymorphisms in other genes might be modifying the risk attributed to by mutations in the primary gene. This showcases the power of combining complimentary physiological and genomic analysis to identify genetic modifiers and potential therapeutic targets of a monogenic disorder. This is extraordinarily critical as we understand on one level that when we sequence a monogenic disorder that there might exist variants of uncertain significance, namely they have not been classified as disease causing, but could be. In turn, we also recognize that mutations in a family might effect different relatives differently. However, why this is has been relatively unclear.                                                 If we can understand and identify those patients who are most at risk of dangerous abnormal rhythms, this will be useful in how much to follow them, and what type of therapy to use in them. The fact that other genes might modify the risk even in the absence of specific mutations, suggests that novel approaches to characterizing the risk might help for the risk modified patients classification in general. Clinical use, however, remains to be seen.                                                 Moving on from long QT, we evaluate 'The Diagnostic Yield of Brugada Syndrome After Sudden Death With Normal Autopsy' noted in last month's issue of the Journal of American College of Cardiology and published by Papadakis et al. It is well known, the negative autopsies are not uncommon in patients, however, families might be wondering how at risk they are. Thus, the authors sought to assess the impact of systematic ajmaline provocation testing using high right precordial leads on the diagnostic yield Brugada syndrome in a large cohort of Sudden Arrhythmic Death syndrome families. Amongst 303 families affected by Sudden Arrhythmic Death Syndrome evaluation was done to determine whether or not there was a genetic inherited channelopathy cause. An inherited cardiac disease was diagnosed in 42% of the families and 22% of relatives Brugada syndrome was the most prevalent diagnosis overall amongst 28% of families. Ajmaline testing was required, however, to unmask the Brugada Syndrome in 97% of diagnosed individuals. Furthermore, they use of high right precordial leads showed a 16% incremental diagnostic yield of ajmaline testing for diagnosing Brugada syndrome.                                                 They further noted that a spontaneous type 1 regard or pattern or a clinically significant rhythmic event developed in 17% of these concealed regardless syndrome patients. The authors concluded the systematic use of ajmaline testing with high right precordial leads increases the yield of Brugada Syndrome testing in Sudden Arrhythmic Death Syndrome families. Furthermore, they noted that assessments should be performed in expert centers or patients could also be counseled appropriately. These findings are important and one of the big questions always becomes how aggressively to test family members of patients or of deceased individuals who experienced sudden arrhythmic death. Many of these patients have negative autopsies, and genetic autopsy might not be possible due to lack of tissue or blood products that can be adequately tested.                                                 The data here suggest that amongst a group of 303 sudden arrhythmic death, families that Brugada Syndrome is by far the most frequent diagnosis. If an inherited cardiac disease was identified. In turn, it is not ECG alone or echo alone that helps identify them, but requires drug provocation testing in addition to different electrode placements. Whether or not this will consistently offer benefit in patients in general or my result in overcalling remains to be seen next within the realm of genetic predisposition.                                                 We view an area where we don't know if there's a genetic predisposition in article published by Tester et al. entitled Cardiac Genetic Predisposition in Sudden Infant Death Syndrome in last month's issue of the journal of american college of cardiology. Sudden Infant Death Syndrome is the leading cause of post-neonatal mortality and genetic heart diseases might underlie some cases of SIDS. Thus the authors sought to determine the spectrum and prevalence of genetic heart disease associated mutations as a potential monogenic basis for Sudden Infant Death Syndrome. They study the largest cohort to date of unrelated SIDS cases, including a total of 419 individuals who underwent whole exome sequencing and targeted analysis for 90 genetic heart disease susceptibility genes. Overall, 12.6% of these cases had at least one potentially informative genetic heart disease associated variants. The yield was higher in those mixed European ancestry than those of European ancestry.                                                 Infants older than four months were more likely to host a potentially informative gene. Furthermore, they noted that only 18 of the 419 SIDS cases hold a [inaudible 01:01:26] or likely pathogenic variant. So in other words, only 4% of cases really had a variant that they could say was distinctly pathogenic or likely pathogenic. Thus, overall, the minority of SIDS cases have potentially informative variant in genetic heart disease susceptibility gene, and these individuals were mostly in the 4 to 12 month age group. Also, only 4% of cases had immediately clinically actionable variance, namely a variant, which is well recognized as pathogenic and where we could actually say that a specific therapy might have had some effect. These findings can have major implications for how best to investigate SIDS cases in families. It might suggest that SIDS cases where the individual was older, nearly 4 to 12 months of age might have a greater yield in terms of identifying variance.                                                 While this might not affect the deceased in fit, it might affect, families are planning on having another child in whom a variant can be identified.                                                 Finally, within the realm of genetics, we review an article published in last month's issue of Science Advances by Huang. et al. entitled 'Mechanisms of KCNQ1 Channel Dysfunction in Long QT Syndrome Involving Voltage Sensor Domain Mutations'. Mutations that induce loss of function of human KCNQ1 underlie the Long QT Syndrome type 1. While hundreds of mutations have been identified the molecular mechanism by which they result in impaired function are not as well understood. The authors sought to investigate impact of 51 specific variants located within the voltage sensor domain and emphasized effect on cell surface expression, protein folding, and structure. For each variant efficiency of trafficking of the plasma membrane, impact of proteasome inhibition, and protein stability were evaluated. They noted that more than half of the loss of function mutations were seen to destabilized structure of the voltage sensor domain, generally accompanied by mistrafficking and degradation by the proteasome.                                                 They also noted that five of the folding defective Long QT Syndrome mutant sites were located in the S0 helix, where they tend to interact with a number of other loss of function mutation sites in other segments of the voltage sensor domain. They suggested these observations reveal a critical role for the S0 helix as a central scaffold to help organize and stabilized KCNQ1 overall. They also note the importance of these findings is that mutation-induced destabilization of membrane proteins may be a more common cause of disease functioning in humans. The importance of these findings lies in better understanding why specific mutations lead to appa

This episode is in memory to Dr. Arthur Moss. We have today Dr. David Auerbach who was a key recent collaborator to review his 2 new recent works with Dr. Moss on the effects of antiseizure and antidepressant medications on LQTS patients. The discussion is very interesting and Dr. Auerbach shares his warm feelings for Dr. Moss with the audience. Finally, we end the podcast with a brief piece of opera.

This episode is in memory to Dr. Arthur Moss. We have today Dr. David Auerbach who was a key recent collaborator to review his 2 new recent works with Dr. Moss on the effects of antiseizure and antidepressant medications on LQTS patients. The discussion is very interesting and Dr. Auerbach shares his warm feelings for Dr. Moss with the audience. Finally, we end the podcast with a brief piece of opera.

Commentary by Dr. Valentin Fuster

Author: Arthur Lessen M.D. Educational Pearls: Zofran (ondansetron) is generally safe to use for the treatment of nausea and vomiting. However, it can prolong the QT interval and increase the chance for torsades.   Low doses of Zofran are not likely to be an issue. However, when multiple doses are given, especially in the setting of a preexisting LQTS, clinical concern should be raised. When giving Zofran to a patient with an increased risk for torsades, consider continuous cardiac monitoring or an alternate anti-emetic.   References:  https://www.fda.gov/Drugs/DrugSafety/ucm310190.htm  

Commentary by Dr. Valentin Fuster

Commentary by Dr. David Wilber

Commentary by Dr. David Wilber

Commentary by Dr. Valentin Fuster

How does a wife, mother and grandmother seize the day when her family has a terrible secret? What secret was in the genes of her, her children and mother that could cause sudden death? How does Jackie help her granddaughters to seize the day?Support the show (https://www.patreon.com/HearttoHeart)

Commentary by Dr. David Wilber

Jedes Jahr sterben in Deutschland zirka 80 - 100.000 Menschen an einem plötzlichen Herztod. Das sind ca. 10 % aller Todesfälle. Bei zirka 10 % der Betroffenen können keine ursächlichen strukturellen Herzerkrankungen erfasst werden. Zu dieser Gruppe gehören genetisch bedingte Arrhythmiesyndrome, wie das Long-QT-Syndrom und das Brugada-Syndrom. Obwohl bisher eine Vielzahl von Mutationen beim LQTS und Brugada-Syndrom identifiziert wurden, sind nur wenige funktionell charakterisiert worden. Große Studien zur Genotyp-Phänotyp Korrelation dieser beiden Erkrankungen basierten bisher auf retrospektiven klinischen Untersuchungen und der Lokalisation nachgewiesener Mutationen. In der vorliegenden Arbeit wurde eine Strategie zur systematischen Untersuchung der Genotyp-Phänotyp-Korrelation bei LQTS und Brugada-Syndrom an vier Patienten mit überlebtem plötzlichen Herztod dargestellt. Durch die funktionelle Expression und elektrophysiologische Untersuchung der identifizierten Mutationen lassen sich individuelle Aussagen über die funktionellen Auswirkungen der Mutation treffen.