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Introduction: The left ventricular summit (LVS) is the highest point on the epicardial surface of the left ventricle. A part of the LVS that is located between the left coronary arteries (lateral‐LVS) is one of the major sites of idiopathic ventricular arrhythmia (VA) origins. Some idiopathic epicardial VAs can be ablated at endocardial sites adjacent to the epicardial area septal to the lateral‐LVS (septal‐LVS). This study examined the prevalence and electrocardiographic and electrophysiological characteristics of septal‐LVS VAs. Methods: We studied consecutive patients with idiopathic VAs originating from the LVS (67 patients) and aortic root (93 patients). Results: Based on the ablation results, among 67 LVS VAs, 54 were classified as lateral and 13 as septal‐LVS VAs. As compared with the lateral‐LVS VAs, the septal‐LVS VAs were characterized by a greater prevalence of left bundle branch block with left inferior‐axis QRS pattern, later precordial transition, lower R‐wave amplitude ratio in leads III to II, lower Q‐wave amplitude ratio in leads aVL to aVR, and later local ventricular activation time relative to the QRS onset during VAs (V‐QRS) in the great cardiac vein. The electrocardiographic and electrophysiological characteristics of the septal‐LVS VAs were similar to those of the aortic root VAs. However, the V‐QRS at the successful ablation site was significantly later during the septal‐LVS VAs than aortic root VAs (p <.0001). The precordial transition was significantly later during the septal‐LVS VAs than aortic root VAs (p <.05). Conclusions: Septal‐LVS VAs are considered a distinct subgroup of idiopathic VAs originating from the left ventricular outflow tract. [ABSTRACT FROM AUTHOR]

Background: The Ventricular fibrillation and flutter (VF/VFL)‐related mortality trends in the United States (US) population have not yet been investigated. We aimed to assess the trends of VT/VFL‐related mortality from 1999 to 2019 among subjects aged more than 15 years old in the US. Methods: Data derived from the Centers for Disease Control and Prevention's (CDC) WONDER were analyzed between 1999 and 2019 for VF/VFL‐related mortality in subjects aged more than 15 years of age. Adjusted mortality rates (AAMRs) per 100,000 people by year, sex, race and urban‐rural status with relative confidence intervals (CIs) were determined. Both the average annual percent change (AAPC) and the annual percent change (APC) with 95% Cis were calculated. Results: Between 1999 and 2019, 242,125 VT/VFL‐related deaths occurred in the US. The overall AAMR steadily declined [AAPC −4.4% (95% CI: −4.7 to −4.0, p <.0001)]. Women showed a more pronounced AAMRs decline [AAPC: −4.8% (95% CI: −5.3 to −4.3, p <.0001). AAMR steadily declined in white subjects and in those of other races [AAPC: −4.5 (95% CI: −4.7 to −4.2, p <.0001) and AAPC: −4.3 (95% CI: −5.1 to −3.5, p <.001), respectively]. Conversely, African Americans showed a steadily AMMR decline between 1999 and 2007 [APC: −8.3 (95% CI: −9.2 to −7.3, p <.0001)], followed by a period of stability from 2007 to 2019 (p =.73). A similar decline was observed for the AAMR among subjects living in urban and rural areas. Conclusions: VT/VFL‐related mortality steadily decreased between 1999 and 2019 in US. Despite the encouraging results, further efforts are needed to prevent VF/VFL‐related mortality in US subjects. [ABSTRACT FROM AUTHOR]

Background: There is a paucity of data regarding the impact of cardiac conduction disease (CD) on clinical outcomes in patients with cardiac amyloidosis (CA)., Methods: The National Inpatient Sample (NIS) was queried to identify all CA admissions and those with CD using ICD-10 codes from 2016 to 2019. We explored baseline characteristics and used multivariate logistic regression to assess the association between CD and several clinical outcomes during index admission; a p-value of <0.05 was significant. Propensity score matching (PSM) was performed to validate our results., Results: A total of 12,185 patients with CA were identified. Of these, 920 (7.6 %) had CD. The median age of the sample was 72 years (IQR: 64-80). After multivariate adjustment and PSM, the presence of CD in CA was associated with higher odds of ventricular arrhythmias (VA) (aOR = 2.97, 95 % CI 1.78-4.96, p < 0.001), syncope (aOR = 3.44, 95 % CI 1.51-7.83, p = 0.003), and cardiovascular implantable electronic device (CIED) implantation (aOR = 12.86, 95 % CI 5.50-30.04, p < 0.001) but not with sudden cardiac arrest (p = 0.092), acute heart failure (p = 0.060), all-cause in-hospital mortality (p = 0.384), and non-routine discharge in patients admitted for CA (p = 0.271)., Conclusions: Although CD was not associated with all-cause in-hospital mortality, there was a significant association with VAs and syncope. Syncope is associated with worse survival in patients with CA. Further studies that prospectively follow patients are needed to determine the true effect of cardiac CD on mortality in patients with CA., Competing Interests: Declaration of competing interest The authors have no conflicts to disclose., (Copyright © 2024. Published by Elsevier B.V.)

Aim: The "2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy" provides recommendations to guide clinicians in the management of patients with hypertrophic cardiomyopathy., Methods: A comprehensive literature search was conducted from September 14, 2022, to November 22, 2022, encompassing studies, reviews, and other evidence on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through May 23, 2023, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate., Structure: Hypertrophic cardiomyopathy remains a common genetic heart disease reported in populations globally. Recommendations from the "2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy" have been updated with new evidence to guide clinicians., (Copyright © 2024 American Heart Association, Inc., and the American College of Cardiology Foundation. Published by Elsevier. Published by Elsevier Inc. All rights reserved.)

Background: Annually 15,200 children suffer an in-hospital cardiac arrest (IHCA) in the US. Ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT) is the initial rhythm in 10-15% of these arrests. We sought to evaluate the association of number of shocks and early dose escalation with survival for initial VF/pVT in pediatric IHCA., Methods: Using 2000-2020 data from the American Heart Association's (AHA) Get with the Guidelines®-Resuscitation (GWTG-R) registry, we identified children >48 hours of life and ≤18 years who had an IHCA from initial VF/pVT and received defibrillation., Results: There were 251 subjects (37.7%) who received a single shock and 415 subjects (62.3%) who received multiple shocks. Baseline and cardiac arrest characteristics did not differ between those who received a single shock versus multiple shocks except for duration of arrest and calendar year. The median first shock dose was consistent with AHA dosing recommendations and not different between those who received a single shock versus multiple shocks. Survival was improved for those who received a single shock compared to multiple shocks. However, no difference in survival was noted between those who received 2, 3, or ≥4 shocks. Of those receiving multiple shocks, no difference was observed with early dose escalation., Conclusions: In pediatric IHCA, most patients with initial VF/pVT require more than one shock. No distinctions in patient or pre-arrest characteristics were identified between those who received a single shock versus multiple shocks. Subjects who received a single shock were more likely to survive to hospital discharge even after adjusting for duration of resuscitation., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: ‘Tia Raymond reports she is a paid consultant of New England Research Institutes, Inc., as a member of the adjudication committee for the COMPASS Trial (Comparison of Methods for Pulmonary Blood Flow Augmentation in Neonates: Shunt versus Stent. Dianne Atkins reports she is a paid member of the Data Monitoring Safety Board for the Pediatric Heart Network, a multicenter study funded by NHLBI’., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Ventricular tachycardia (VT) and ventricular fibrillation (VF) are life-threatening conditions and can be refractory to conventional drug and device interventions. Stellate ganglion blockade (SGB) has been described as an adjunct, temporizing intervention in patients with refractory ventricular arrhythmia. We examined the association of SGB with VT/VF in a multicenter registry., Objectives: This study examined the efficacy of SGB for treatment/temporization of refractory VT/VF., Methods: The authors present the first analysis from a multicenter registry of patients treated for refractory ventricular arrhythmia at a clinical site in the Czech Republic and the United States. Data were collected between 2016 and 2022. SGB was performed at the bedside by anesthesiologists and/or cardiologists. Outcomes of interest were VT/VF burden and defibrillations at 24 hours before and after SGB., Results: In total, there were 117 patients with refractory ventricular arrhythmias treated with SGB at Duke (n = 49) and the Institute for Clinical and Experimental Medicine (n = 68). The majority of patients were male (94.0%), were White (87.2%), and had an implantable cardioverter-defibrillator (70.1%). The most common etiology of heart disease was ischemic cardiomyopathy (52.1%), and monomorphic VT was the most common morphology (70.1%). Within 24 hours before SGB (0-24 hours), the median episodes of VT/VF were 7.5 (Q1-Q3: 3.0-27.0), and 24 hours after SGB, the median decreased to 1.0 (Q1-Q3: 0.0-4.5; P < 0.001). At 24 hours before SGB, the median defibrillation events were 2.0 (Q1-Q3: 0.0-8.0), and 24 hours after SGB, the median decreased to 0.0 (Q1-Q3: 0.0-1.0; P < 0.001)., Conclusions: In the largest cohort of patients with treatment-refractory ventricular arrhythmia, we demonstrate that SGB use was associated with a reduction in the ventricular arrhythmia burden and need for defibrillation therapy., Competing Interests: Funding Support and Author Disclosures Dr Piccini is a consultant for Abbott, Biotronik, Boston Scientific, Medtronic, and Philips; has received grants for clinical research from Abbott, the American Heart Association, Boston Scientific, and Philips; and is supported by R01AG074185 from the National Institutes of Aging. Dr Fudim has been supported by the American Heart Association (20IPA35310955), Doris Duke, and Bodyport and has received consulting fees from Abbott, Boston Scientific, Presidio, and Zoll. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Published by Elsevier Inc.)

Aim This executive summary of the hypertrophic cardiomyopathy clinical practice guideline provides recommendations and algorithms for clinicians to diagnose and manage hypertrophic cardiomyopathy in adult and pediatric patients as well as supporting documentation to encourage their use. Methods A comprehensive literature search was conducted from January 1, 2010, to April 30, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Structure Many recommendations from the earlier hypertrophic cardiomyopathy guidelines have been updated with new evidence or a better understanding of earlier evidence. This summary operationalizes the recommendations from the full guideline and presents a combination of diagnostic work-up, genetic and family screening, risk stratification approaches, lifestyle modifications, surgical and catheter interventions, and medications that constitute components of guideline directed medical therapy. For both guideline-directed medical therapy and other recommended drug treatment regimens, the reader is advised to follow dosing, contraindications and drug-drug interactions based on product insert materials. [ABSTRACT FROM AUTHOR]

Sudden cardiac death is a tragedy at any age and under any circumstances, but it is perhaps more tragic when it appears in the athlete, a person who has a healthy lifestyle. Regular physical activity and physical performance training ensure a good functioning of the cardiovascular system. However, there are situations of unfavorable evolution, which are diagnosed as sudden cardiac death (SCD) in athletes. Obstructive hypertrophic cardiomyopathy - in the US - and arrhythmogenic right ventricular cardiomyopathy - in Europe - are the two leading causes of sudden cardiac death to young athletes. Sudden cardiac death in athletes is the leading cause of medical death in this subgroup, with an estimated incidence of 1 in 50,000 to 1 in 80,000 athletes per year. [ABSTRACT FROM AUTHOR]

Background: There are no published human studies investigating whether the use of allopurinol, the most commonly used medication for the treatment of hyperuricemia in gout, the most common type of inflammatory arthritis in adults, has any beneficial effects on ventricular electrophysiology. The objective of our study was to assess whether allopurinol use is associated with a reduction in the risk of ventricular arrhythmias (VA).Methods: We used the 5% random sample of Medicare beneficiaries from 2006-2012 to examine new allopurinol use and the risk of incident VA. Multivariable Cox regression analyses were adjusted for demographics (age, race, sex), comorbidity, cardiac medications, and conditions associated with VA. We calculated hazard ratios (HR) and 95% confidence intervals (CI).Results: Of the 28,755 episodes of new allopurinol use, 2538 were associated with incident VA (8.8%). Among patients with incident VA, 54% were male, 78% were White, 75% had gout as the underlying diagnosis, and the mean Charlson-Romano comorbidity score was 4.8. The crude incidence of VA per 1,000,000 person-days declined as the duration of allopurinol use increased: 1-180 days, 151; 181 days to 2 years, 105; and > 2 years, 85. In multivariable-adjusted analyses, compared to non-use, allopurinol use was associated with lower HR of VA of 0.82 (95% CI, 0.76-0.90). Compared to allopurinol non-use, longer allopurinol use durations were significantly associated with lower multivariable-adjusted HR for VA: 1-180 days, 0.96 (95% CI, 0.85-1.08); 181 days to 2 years, 0.76 (95% CI, 0.68-0.85); and > 2 years, 0.72 (95% CI, 0.60-0.87). Multiple sensitivity analyses adjusting for cardiac conditions, anti-arrhythmic drugs and alternate definitions confirmed our findings with minimal/no attenuation of estimates.Conclusion: Allopurinol use and use duration of more than 6 months were independently associated with a lower risk of VA. Future studies need to assess the pathophysiology of this potential benefit. [ABSTRACT FROM AUTHOR]

Background: The wearable cardioverter-defibrillator (WCD) prevents sudden cardiac death due to ventricular tachycardia (VT) or ventricular fibrillation (VF) but does not pace for post-shock asystole (PS-A) or bradycardia (PS-B;<50 beats/ min)., Objectives: The purpose of this study was to assess PS-A and PS-B in patients dying out of hospital (OOH) while wearing a WCD., Methods: The database of the U.S. Food and Drug Administration Manufacturers and User Facility Device Experience (MAUDE) was queried for manufacturers' reports of OOH deaths while patients were wearing a WCD. Excluded were patients who did not receive a shock or were initially shocked for asystole or during resuscitation., Results: From January 2017 to March 2022, 313 patients received an initial WCD shock for VF (n = 150), VT (n = 90), and non-VF/VT rhythms (n = 73). PS-A occurred in 204 patients (65.2%), and PS-B occurred in 111 (35.5%); 85 (41.7%) PS-A patients also had PS-B. Most PS-A patients (n = 185; 90.7%) had an initial shocked rhythm of VF or VT, but 19 patients (9.3%) were initially inappropriately shocked for atrial fibrillation/supraventricular tachycardia (n = 7) and idioventricular (n = 8) or sinus (n = 4) rhythm. PS-A occurred after the first WCD shock in 118 (63.8%) and after the first, second, or third shocks in 159 patients (85.9%). Seven patients had post-shock heart block. Eight patients had permanent pacemakers; 1 became nonfunctional after 1 shock, and 7 showed noncapture and/or asystole after 1 to 4 shocks., Conclusions: Post-shock asystole appears to be common in patients who die OOH after being shocked by a WCD for VF or VT. PS-A also occurs after inappropriate WCD shocks for non-VF/VT rhythms. Implanted pacemakers may not prevent PS-A after a WCD shock. WCD backup pacing should be explored., Competing Interests: Funding Support and Author Disclosures The Minneapolis Heart Institute Foundation funded this study. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2023 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

A new guideline for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death has been published by the European Society of Cardiology (ESC). Beside the 2017 American Heart Association/American College of Cardiology/Heart Rhythm Society (AHA/ACC/HRS) guideline and the 2020 Canadian Cardiovascular Society/Canadian Heart Rhythm Society (CCS/CHRS) position statement, this guideline provides evidence-based recommendations for clinical practice. As these recommendations are periodically updated integrating the latest scientific evidence, there are similarities in many aspects. Nevertheless, notable differences in the recommendations can be found resulting from different scopes and publication years, differences in data selection, interpretation, and weighing, and regional factors such as differing drug availability. The aim of this paper is to compare specific recommendations to identify differences while acknowledging the commonalities and to provide an overview of the status of current recommendations with a special emphasis on gaps in evidence and future directions of research. Overall, the recent ESC guideline places a greater emphasis on the value of cardiac magnetic resonance, genetic testing in cardiomyopathies and arrhythmia syndromes, and the use of risk calculators for risk stratification. Further significant differences can be found regarding diagnostic criteria for genetic arrhythmia syndromes, the management of hemodynamically well-tolerated ventricular tachycardia, and primary preventive implantable cardioverter-defibrillator therapy., Competing Interests: Funding Support and Author Disclosures Dr Eckardt has received lecture fees from Abbott, Bayer, Boston Scientific, Daiichi Sankyo, Medtronic, Biotronik, Sanofi Aventis, and Bristol Myers Squibb. Dr Zeppenfeld has received research funding from Biosense Webster (research electrophysiology). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2023 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Brugada syndrome (BrS) is a severe inherited arrhythmia syndrome that can be unmasked by fever., Methods: A multicentre clinical analysis was performed in 261 patients diagnosed with fever-induced BrS, including 198 (75.9%) and 27 (10.3%) patients who received next-generation genetic sequencing and epicardial arrhythmogenic substrate (AS) mapping, respectively., Findings: In fever-induced BrS patients, pathogenic or likely pathogenic (P/LP) SCN5A variant carriers developed fever-induced BrS at a younger age, and more often in females and those of Caucasian descent. They exhibited significant electrophysical abnormalities, including a larger epicardial AS area, and more prolonged abnormal epicardial electrograms. During a median follow-up of 50.5 months (quartiles 32.5-81.5 months) after the diagnosis, major cardiac events (MCE) occurred in 27 (14.4%) patients. Patients with P/LP SCN5A variants had a higher ratio of MCE compared with the rest. Additionally, history of syncope, QRS duration, and Tpe interval could also predict an increased risk for future MCE according to univariate analysis. Multivariate analysis indicated that only P/LP SCN5A variants were independent significant predictors of MCE. Computational structural modelling showed that most variants are destabilizing, suggesting that Nav1.5 structure destabilization caused by SCN5A missense variants may contribute to fever-induced BrS., Interpretation: In our cohort, P/LP SCN5A variant carriers with fever-induced BrS are more prevalent among patients of Caucasian descent, females, and younger patients. These patients exhibit aggressive electrophysiological abnormalities and worse outcome, which warrants closer monitoring and more urgent management of fever., Funding: The current work was supported by the National Natural Science Foundation Project of China (Nos. 82270332 & 81670304), The Fundamental Research Funds for the Central Universities of China - Independent Research Project of Wuhan University (No. 2042022kf1217) from China; the National Institutes of Health of USA [NIH R56 (HL47678), NIH R01 (HL138103), and NIH R01 (HL152201)], the W. W. Smith Charitable Trust and the Wistar and Martha Morris Fund, Sharpe-Strumia Research Foundation, the American Heart Association Postdoctoral Fellowship (20POST35220002) from United States; the Netherlands CardioVascular Research Initiative: the Dutch Heart Foundation, Dutch Federation of University Medical Centers, the Netherlands Organization for Health Research and Development, and the Royal Netherlands Academy of Sciences (PREDICT2) from the Netherlands., Competing Interests: Declaration of interests Dr. Antzelevitch served as a consultant and received grant funds from Novartis and Trevena Inc. Dr. Wilde served as a consultant for LQTtherapeutics. All other authors report no relationships to disclose., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Background Cardiovascular disease and sudden cardiac arrest are the leading causes of death in the United States. Early defibrillation is key to successful resuscitation for patients who experience shockable rhythms during a cardiac arrest. It is therefore vital that the shock advisory of AEDs (automated external defibrillators) or defibrillators in AED mode be reliable and appropriate. The goal of this study was to better understand the performance of multiple lay-rescuer and hospital professional defibrillators in AED mode in their analysis of ventricular arrhythmias. The measurable objectives of this study sought to quantify: 1. No shock advisory for sinus rhythms at any rate. 2. Recognition and shock advisory for ventricular fibrillation (VF). 3. Recognition and shock advisory for monomorphic ventricular tachycardia (VT). 4. Recognition and shock advisory for Torsades de Pointes (TdP). Methods This is a prospective evaluation of two AEDs and four semi-automatic, hospital professional defibrillators. This study represents post-marketing evaluation of FDA approved devices. Each defibrillator was connected to multiple rhythm simulators and presented with simulated ECG waveforms 20 consecutive times at various rates when possible. Results All four defibrillators and both AEDs tested consistently recognized normal sinus rhythm (NSR) from all rhythm sources, and did not recommend a shock for NSR at any rate (from 80 to 220 bpm). All four defibrillators and both AEDs recognized VF from all rhythm sources tested and recommended a shock 100% of the time. Variations were found in the shock advisory rates among defibrillators when testing simulated VT heart rates at or below 150 bpm. One AED tested did not consistently advise a shock for monomorphic VT or TdP at any tested rate. Conclusion Lay-rescuer AEDs and professional hospital defibrillators tested in AED mode did not reliably recommend a shock for sustained monomorphic VT or TdP at certain rates, despite the fact that it is a critical component of the currently recommended treatment. These findings require further examination of the risk benefit analysis of shocking or not shocking rhythms such as TdP or pulseless VT. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to assess, among Japanese patients with cardiac sarcoidosis (CS), the implantable cardioverter-defibrillator (ICD) recommendations from the 2017 American Heart Association/American College of Cardiology/Heart Rhythm Society (AHA/ACC/HRS) guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death (SCD)., Background: Although ICDs are used to prevent SCD from ventricular tachycardia or ventricular fibrillation (VT/VF) in patients with CS, the generalizability of the AHA/ACC/HRS guidelines for Japanese patients with CS remains unclear., Methods: This study examined 188 consecutive patients with CS in 2 tertiary hospitals between 1979 and 2020. Patients were followed for a primary outcome of VT/VF or SCD., Results: During a median follow-up of 5.68 years, the primary outcome occurred in 44 patients (23%). Patients with a Class I recommendation for ICD implantation showed the highest incidence of the primary outcome among patients in whom the guideline recommendations for ICD implantation were used (log-rank test; p = 0.03). However, compared with patients with left ventricular ejection fractions (LVEFs) ≤35%, there was no significant difference in the incidence of the primary outcome among patients with LVEFs >35% and those who required a permanent pacemaker (p = 0.31); similar results were observed in those with LVEFs >35% and late gadolinium enhancement during cardiovascular magnetic resonance imaging (p = 0.22)., Conclusions: The American guideline recommendations for ICD implantation might be applicable to Japanese patients with CS. Implantation of an ICD may need to be considered in these patients if they require a permanent pacemaker or have late gadolinium enhancement, regardless of LVEF., Competing Interests: Funding Support and Author Disclosures Dr. Nagai was supported by a Grant-in-Aid for Young Scientists from the Japan Society for the Promotion of Science (15K19402) and by a grant from the Japan Heart Foundation. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Data on the arrhythmic burden of women at risk for sudden cardiac death are limited, especially in patients using the wearable cardioverter-defibrillator (WCD)., Objective: We aimed to characterize WCD compliance, atrial and ventricular arrhythmic burden, and WCD outcomes by sex in patients enrolled in the Prospective Registry of Patients Using the Wearable Cardioverter Defibrillator (WEARIT-II U.S. Registry)., Methods: In the WEARIT-II Registry, we stratified 2000 patients by sex into women (n = 598) and men (n = 1402). WCD wear time, ventricular and atrial arrhythmic events during WCD use, and implantable cardioverter-defibrillator (ICD) implantation rates at the end of WCD use were evaluated., Results: The mean WCD wear time was similar in women and men (94 days vs 90 days; P = .145), with longer daily use in women (21.4 h/d vs 20.7 h/d; P = .001). Burden of ventricular tachycardia or ventricular fibrillation was higher in women, with 30 events per 100 patient-years compared with 18 events per 100 patient-years in men (P = .017), with similar findings for treated and non-treated ventricular tachycardia/ventricular fibrillation. Recurrent atrial arrhythmias/sustained ventricular tachycardia was also more frequent in women than in men (167 events per 100 patient-years vs 73 events per 100 patient-years; P = .042). However, ICD implantation rate at the end of WCD use was similar in both women and men (41% vs 39%; P = .448)., Conclusion: In the WEARIT-II Registry, we have shown a higher burden of ventricular and atrial arrhythmic events in women than in men. ICD implantation rates at the end of WCD use were similar. Our findings warrant monitoring women at risk for sudden cardiac death who have a high burden of atrial and ventricular arrhythmias while using the WCD., (Copyright © 2020 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Aim: This executive summary of the hypertrophic cardiomyopathy clinical practice guideline provides recommendations and algorithms for clinicians to diagnose and manage hypertrophic cardiomyopathy in adult and pediatric patients as well as supporting documentation to encourage their use., Methods: A comprehensive literature search was conducted from January 1, 2010, to April 30, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases., Structure: Many recommendations from the earlier hypertrophic cardiomyopathy guidelines have been updated with new evidence or a better understanding of earlier evidence. This summary operationalizes the recommendations from the full guideline and presents a combination of diagnostic work-up, genetic and family screening, risk stratification approaches, lifestyle modifications, surgical and catheter interventions, and medications that constitute components of guideline directed medical therapy. For both guideline-directed medical therapy and other recommended drug treatment regimens, the reader is advised to follow dosing, contraindications and drug-drug interactions based on product insert materials., (Copyright © 2020 American Heart Association, Inc., and the American College of Cardiology. Published by Elsevier Inc. All rights reserved.)

Cardiac denervation is associated with progressive left ventricular (LV) dysfunction, ventricular arrhythmias, and sudden cardiac death (SCD) in heart failure (HF). In this regard, it is important to evaluate cardiac-specific sympathetic nervous system (SNS) function. The radiotracer Iodine-123 meta-iodobenzylguanidine ( 123 I-mIBG) can noninvasively evaluate pre-synaptic SNS function. Recent multicenter trials have shown 123 I-mIBG to have strong predictive value for fatal arrhythmias and cardiac death in HF. 123 I-mIBG was initially developed in the USA in the 1970s. In 1992, the Japanese Ministry of Health and Labour approved 123 I-mIBG for the assessment of cardiac function. Following approval, the Japanese nuclear cardiology community developed 123 I-mIBG imaging services in various medical centers. Japanese groups have been trying to establish the clinical utility of 123 I-mIBG and standardize parameters for data acquisition and image analysis. The US Food and Drug Administration (FDA) has approved clinical use of 123 I-mIBG for cardiac and non-cardiac imaging. However, clinical use of 123 I-mIBG in the US has been very limited. The number of 123 I-mIBG studies in Japan has also been limited. There are similarities and differences between the two countries. To establish the clinical utility of 123 I-mIBG in both countries, it is important to characterize the situations of 123 I-mIBG in each.

This is a review of the 2017 AHA/ACC/HRS Guidelines with guidance for intraoperative physicians. Ventricular arrhythmias occurring during the perioperative period have the potential for significant morbidity and mortality. Hence, an in-depth knowledge of VA mechanisms, prevention, and management is crucial for all clinicians caring for these at-risk patients in the perioperative period. Perioperative optimization of patients with a known or suspected VA should be tailored to the specific patient population and condition as outlined in this manuscript., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Although large randomized clinical trials have found that primary prevention use of an implantable cardioverter-defibrillator (ICD) improves survival in patients with cardiomyopathy and heart failure symptoms, patients who receive ICDs in practice are often older and have more comorbidities than patients who were enrolled in the clinical trials. In addition, there is a debate among clinicians on the usefulness of electrophysiological study for risk stratification of asymptomatic patients with Brugada syndrome., Aim: Our analysis has 2 objectives. First, to evaluate whether ventricular arrhythmias (VAs) induced with programmed electrostimulation in asymptomatic patients with Brugada syndrome identify a higher risk group that may require additional testing or therapies. Second, to evaluate whether implantation of an ICD is associated with a clinical benefit in older patients and patients with comorbidities who would otherwise benefit on the basis of left ventricular ejection fraction and heart failure symptoms., Methods: Traditional statistical approaches were used to address 1) whether programmed ventricular stimulation identifies a higher-risk group in asymptomatic patients with Brugada syndrome and 2) whether ICD implantation for primary prevention is associated with improved outcomes in older patients (>75 years of age) and patients with significant comorbidities who would otherwise meet criteria for ICD implantation on the basis of symptoms or left ventricular function., Results: Evidence from 6 studies of 1138 asymptomatic patients were identified. Brugada syndrome with inducible VA on electrophysiological study was identified in 390 (34.3%) patients. To minimize patient overlap, the primary analysis used 5 of the 6 studies and found an odds ratio of 2.3 (95% CI: 0.63-8.66; p=0.2) for major arrhythmic events (sustained VAs, sudden cardiac death, or appropriate ICD therapy) in asymptomatic patients with Brugada syndrome and inducible VA on electrophysiological study versus those without inducible VA. Ten studies were reviewed that evaluated ICD use in older patients and 4 studies that evaluated unique patient populations were identified. In our analysis, ICD implantation was associated with improved survival (overall hazard ratio: 0.75; 95% confidence interval: 0.67-0.83; p<0.001). Ten studies were identified that evaluated ICD use in patients with various comorbidities including renal disease, chronic obstructive pulmonary disease, atrial fibrillation, heart disease, and others. A random effects model demonstrated that ICD use was associated with reduced all-cause mortality (overall hazard ratio: 0.72; 95% confidence interval: 0.65-0.79; p<0.0001), and a second "minimal overlap" analysis also found that ICD use was associated with reduced all-cause mortality (overall hazard ratio: 0.71; 95% confidence interval: 0.61-0.82; p<0.0001). In 5 studies that included data on renal dysfunction, ICD implantation was associated with reduced all-cause mortality (overall hazard ratio: 0.71; 95% confidence interval: 0.60-0.85; p<0.001)., (Copyright © 2018 American College of Cardiology Foundation, the American Heart Association, Inc., and the Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: This study investigated the prevalence, electrocardiographic and electrophysiological characteristics, and ablation outcome of idiopathic ventricular arrhythmias (VAs) originating from the infundibular muscles (IFMs) in the right ventricle consisting of the parietal band (PB) and septal band (SB)., Methods and Results: We studied 19 patients with idiopathic VA origins in the PB in 14 and SB in 5 among 294 consecutive patients with VA origins in the right ventricle. PB and SB VAs exhibited left bundle branch block with a left inferior (n=12) or superior (n=2) axis and left (n=4) or right inferior (n=1) axis pattern, respectively. In lead I, all PB VAs exhibited R waves while SB VAs often exhibited S waves. A QS pattern in lead aVR and the presence of a notch in the mid-QRS were common in all IFMs VAs. During IFMs VAs, a far-field ventricular electrogram with an early activation was always recorded in the His bundle region regardless of the location of the VA origins. With 9.2±6.9 radiofrequency applications and a duration of 972±946 seconds, catheter ablation was successful in 15 patients. VAs recurred in 4 during a follow-up period of 43±24 months. A change in the QRS morphology was observed spontaneously in 5 patients, immediately after ablation in 4, and at the time of the VA recurrence in 2., Conclusions: Idiopathic VAs originating from the IFMs are rare (PB>SB). Catheter ablation of these IFMs VAs was challenging, requiring a large amount of the radiofrequency energy delivery for a successful ablation with a relatively high recurrence rate., (© 2018 American Heart Association, Inc.)

Background: Reduced left ventricular (LV) ejection fraction increases the risk of ventricular arrhythmias; however, LV ejection fraction has a low sensitivity to predict ventricular arrhythmias. LV dilatation and mass may be useful to further risk-stratify for ventricular arrhythmias., Methods and Results: Patients from the Genetic Risk of Assessment of Defibrillator Events (GRADE) study (N=930), a study of heart failure subjects with defibrillators, were assessed for appropriate implantable cardioverter-defibrillator shock and death, heart transplant, or ventricular assist device placement by LV diameter and mass. LV mass was divided into normal, mild, moderate, and severe classifications. Severe LV end-diastolic diameter had worse shock-free survival than normal and mild LV end-diastolic diameter (P=0.0002 and 0.0063, respectively; 2-year shock free, severe 74%, moderate 80%, mild 91%, normal 88%; 4-year shock free, severe 62%, moderate 69%, mild 72%, normal 81%) and freedom from death, transplant, or ventricular assist device compared with normal and moderate LV end-diastolic diameter (P<0.0001 and 0.0441, respectively; 2-year survival: severe 78%, moderate 85%, mild 82%, normal 89%; 4-year survival: severe 55%, moderate 64%, mild 63%, normal 74%). Severe LV mass had worse shock-free survival than normal and mild LV mass (P=0.0370 and 0.0280, respectively; 2-year shock free: severe 80%, moderate 81%, mild 91%, normal 87%; 4-year shock free: severe 68%, moderate 73%, mild 76%, normal 76%) but no association with death, transplant, or ventricular assist device (P=0.1319). In a multivariable Cox proportional hazards analysis adjusted for LV ejection fraction, LV end-diastolic diameter was associated with appropriate implantable cardioverter-defibrillator shocks (hazard ratio 1.22, P=0.020). LV end-diastolic diameter was associated with time to death, transplant, or ventricular assist device (hazard ratio 1.29, P=0.0009)., Conclusions: LV dilatation may complement ejection fraction to predict ventricular arrhythmias., Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02045043., (© 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)