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Although ventricular dysfunction is associated with the occurrence of ventricular arrhythmia (VA), most patients with cardiomyopathy do not experience VA. We therefore investigated other predictors of VA in a large contemporary cohort of patients with cardiomyopathy. All patients at a large academic medical system with left ventricular ejection fraction (LVEF) ≤50% were enrolled at the time of first documented low LVEF. Predictors of hospital admission for VA were examined using multivariable Cox models. The incidence of implantable defibrillator (ICD) placement was also examined. A total of 18,003 patients were enrolled. Over a median follow-up of 3.35 years, 389 patients (2.2%) were admitted for VA (304 of 12,037 [2.5%] among patients with LVEF ≤35% vs 85 of 5,966 [1.4%] among those with LVEF 36% to 50%). Predictors of VA hospitalization included lower LVEF (hazard ratio (HR) = 1.43 per 10% decrease, p0.001), the presence of an ICD at baseline (HR = 1.63, p = 0.010), higher blood glucose (HR = 1.02 per 10 mg/100 ml increase, p = 0.050), the presence of end-stage renal disease (HR = 3.59, p0.001), and the presence of liver cirrhosis (HR = 1.93, p = 0.013). During follow-up, 626 patients were implanted with a new ICD. In addition to being admitted with VA, a lower LVEF and a history of coronary artery disease or heart failure were the main predictors of ICD therapy in this population. In conclusion, in addition to more severe cardiomyopathy and the presence of an implanted ICD, metabolic derangements on initial contact are independent predictors of hospital admissions for VA in patients with cardiomyopathy. Noncardiac co-morbidities play an important role in stratifying patients with cardiomyopathy for their risk of VA or cardiac arrest.

INTRODUCTION Pacing-induced cardiomyopathy (PICM) is a potential complication of chronic right ventricular (RV) pacing, but its characterization in adult patients is often complicated by pre-existing cardiomyopathy. This study investigated the incidence of PICM in patients with congenital heart block (cHB) who have conduction disease from birth without confounding pre-existing cardiac conditions. METHODS AND RESULTS This retrospective cohort analysis included 42 patients with cHB and baseline left ventricular ejection fraction (LVEF) ≥50%. Kaplan-Meier analysis was used to assess freedom from cardiomyopathy (defined as LVEF

Background Obesity is a worldwide epidemic that has been associated with poor outcomes. Previous studies have demonstrated an inverse relationship between body mass index (BMI) and outcomes, the 'obesity paradox', in several diseases. Hypothesis We sought to evaluate whether the obesity paradox is present in patients with left ventricular systolic dysfunction (LVSD) of all etiologies, using all‐cause mortality as the primary endpoint and hospitalization as the secondary endpoint. Methods We conducted a retrospective cohort study of LVSD patients (n = 18 003) seen within the University of Pittsburgh Medical Center network between January 2011 and December 2017. Patients were divided into four BMI categories (underweight, normal weight, overweight, and obese) and stratified by left ventricular ejection fraction (LVEF)

Contemporary guideline-directed medical therapy (GDMT) confers a significant mortality benefit for patients with heart failure with reduced ejection fraction (HFrEF), as compared to GDMT prevalent at the time of landmark primary prevention implantable cardioverter-defibrillator (ICD) trials. The impact of modern era GDMT on survival in this population is unknown.This study sought to investigate the impact of number of GDMT medications prescribed for HFrEF on all-cause mortality in recipients of primary prevention ICD.A cohort of 4,972 recipients with primary prevention ICD (n = 3,210) or cardiac resynchronization therapy-defibrillator (CRT-D) (n = 1,762) was studied. The association of number of GDMT medications prescribed at the time of device implantation and all-cause mortality at 2 years post implantation was examined.In our primary prevention cohort, 5%, 20%, 52%, and 23% of patients were prescribed 0, 1, 2, or 3-4 GDMT medications, respectively. After risk adjustment for age, sex, ejection fraction, body mass index, the Elixhauser comorbidity score, the type of cardiomyopathy, and the year of device implantation, each additional GDMT conferred a reduction in the risk of death of 36% in recipients of ICD (HR: 0.64; P 0.001) and 30% in recipients of CRT-D (HR: 0.70; P 0.001).A higher number of prescribed GDMT medications is associated with an incremental 1-year survival in recipients of primary prevention ICD with or without CRT. Initiation of maximum number of tolerated GDMT medications should therefore be the goal for all patients with HFrEF. In the setting of robust GDMT, the risk versus benefit of a primary prevention ICD warrants re-examination in future studies.

Atrial Fibrillation (AF) is the most common arrhythmia in adults, and the rapid increase in AF prevalence has been classified by experts as an epidemic. The mechanisms of AF are complex and incompletely understood. While many aspects of management are now based on high quality evidence, other clinical decisions are based on experience and judgment. This article provides an up to date review relating to lifestyle modification and its effect on AF to inform clinical treatment. This comprehensive review used PubMed and Google Scholar to perform keyword searches of articles published between 1998 and the present, with the exception of the 1978 "Holiday Heart" article. Robust data has emerged identifying multiple risk factors for development of AF, including age, sex, hypertension, diabetes mellitus, obesity, alcohol consumption, exercise, and obstructive sleep apnea. Recent evidence indicates that lifestyle modification has a significant role in mitigating the risk and burden of AF. In conclusion, based on the available evidence, an interdisciplinary approach to lifestyle modification will likely reduce risk and/or symptom burden of AF.

Patients with atrial fibrillation (AF) commonly have impaired renal function. The safety and efficacy of direct oral anticoagulants (DOACs) in patients with chronic kidney disease (CKD) and end-stage renal disease has not been fully elucidated. This study evaluated and compared the safety outcomes of DOACs versus warfarin in patients with nonvalvular AF and concomitant CKD. Patients in our health system with AF prescribed oral anticoagulants during 2010 to 2017 were identified. All-cause mortality, bleeding and hemorrhagic, and ischemic stroke were evaluated based on degree of renal impairment and method of anticoagulation. There were 21,733 patients with a CHA2DS2-VASc score of ≥2 included in this analysis. Compared with warfarin, DOAC use in patients with impaired renal function was associated with lower risk of mortality with a hazard ratio (HR): 0.76 (95% confidence interval [CI] 0.70 to 0.84, p value 60, HR 0.74 (95% CI 0.68 to 0.81, p value 30 to 60, and HR 0.76 (95% CI 0.63 to 0.92, p value 60, HR 0.83 (95% CI 0.74 to 0.94, p value 0.003) in patients with eGFR >30 to 60, and HR 0.69 (95% CI 0.50 to 0.93, p value 0.017) in patients with eGFR ≤30 or on dialysis. In conclusion, in comparison to warfarin, DOACs appear to be safe and effective with a lower risk of all-cause mortality and lower bleeding across all levels of CKD.

INTRODUCTION Patients eligible for primary prevention implantable cardioverter-defibrillator (ICD) therapy are faced with a complex decision that needs a clear understanding of the risks and benefits of such an intervention. In this study, our goal was to explore the documentation of primary prevention ICD discussions in the electronic medical records (EMRs) of eligible patients. METHODS In 1523 patients who met criteria for primary prevention ICD therapy between 2013 and 2015, we reviewed patient charts for ICD-related documentation: "mention" by physicians or "discussion" with patient/family. The attitude of the physician and the patient/family toward ICD therapy during discussions was categorized into negative, neutral, or positive preference. Patients were followed to the end-point of ICD implantation. RESULTS Over a median follow-up of 442 days, 486 patients (32%) received an ICD. ICD was mentioned in the charts of 1105 (73%) patients, and a discussion with the patient/family about the risks and benefits of ICD was documented in 706 (46%) charts. On multivariable analyses, positive cardiologist (hazard ratio [HR]: 7.9, 95% confidence of intervals [CI]: 1.0-59.7, P

A re-designed single chamber leadless pacemaker (LP; Aveir) was developed with the goal of improving safety and performance of its predecessor (Nanostim). Herein, we present the first-in-human expe...

Objectives This study sought to investigate the impact of the neurological status of sudden cardiac arrest (SCA) survivors on implantable cardioverter-defibrillator (ICD) insertion and long-term mortality. Background The neurological status of SCA survivors may impact the decision to insert an ICD insertion and influence long-term survival. Methods In 1,433 survivors of SCA between 2002 and 2012, we examined the neurological status immediately after the arrest using the Pittsburgh Cardiac Arrest Category (PCAC) and prior to hospital discharge using the cerebral performance category (CPC) score. Patients were followed up to the endpoints of ICD implantation and all-cause mortality. Results Over a median follow-up period of 3.6 years, 389 (27%) patients received an ICD, and 674 (47%) died. The PCAC (adjusted hazard ratio [HR]: 0.79; 95% confidence interval [CI]: 0.69 to 0.90) and CPC (adjusted HR: 0.73; 95% CI: 0.64 to 0.84) scores were highly predictive of the time to ICD insertion and of all-cause mortality (PCAC score, adjusted HR: 1.39; 95% CI: 1.24 to 1.57; CPC score, adjusted HR: 2.03; 95% CI: 1.77 to 2.34). ICD therapy was associated with better survival even after adjusting for neurological status (HR: 0.56; 95% CI: 0.43 to 0.73). A significant proportion of patients in the worse CPC categories had a >1-year survival after the index SCA. Conclusions In SCA survivors, worse neurological performance was associated with lower likelihood of ICD insertion and higher mortality. ICD insertion was associated with improved survival even after accounting for neurological performance. ICD discussion should therefore not be omitted in these patients.

In patients with hypertrophic cardiomyopathy (HC), atrial fibrillation (AF) is common, often poorly tolerated and difficult to treat. Limited data exists regarding safety or efficacy of drug therapy for AF rhythm control in HC patients. We performed a retrospective analysis of patients with HC followed >6 months, treated with amiodarone, sotalol, dofetilide, or disopyramide for rhythm control of non-postoperative AF. The duration followed on each medication, reasons for discontinuing, and incidences of adverse events were recorded. Confounding factors including maximum ventricular septal thickness, age, left ventricular ejection fraction, and gender were assessed. Ninety-eight patients had 130 drug treatments (defined as a continuous time on 1 drug); 23 patients were treated with >1 medication. The probability of remaining on a single antiarrhythmic drug at 1 year was 62% and at 3 was 42%. Maximum ventricular septal thickness (hazard ratio 1.05, p = 0.03) and presence of resting outflow gradient (hazard ratio 2.50, p = 0.002) were associated with discontinuation of therapy. Patients treated with amiodarone or sotalol had no serious safety events suggesting that these medications may be reasonably safe. Amiodarone was least likely to be discontinued for inefficacy (8.5%), but likely to be discontinued for side effects (19%). The probability of remaining on sotalol was 74% at 1 year and 50.0% at 3 and it was only discontinued for side effects in 2%. A small number of patients were treated with disopyramide and dofetilide. In conclusion, our data suggest that amiodarone and sotalol are likely safe, and that sotalol may be particularly attractive given its low rate of side effects and low rate of discontinuation.

Moderate-intensity exercise improves cardiovascular outcomes. However, mounting clinical evidence demonstrates that long-term, high-intensity endurance training predisposes male and veteran athletes to an increased risk of atrial fibrillation (AF), a risk that is not observed across both genders. Although increased mortality associated with AF in the general population is not shared by athletes, clinically significant morbidities exist (eg, reduced exercise capacity, athletic performance, and quality of life). Additional research is needed to fill current gaps in knowledge pertaining to the natural history, pathophysiologic mechanisms, and management strategies of AF in the athlete.

Racial disparities in health outcomes have been widely documented in medicine, including in cardiovascular care. While some progress has been made, these disparities have continued to plague our healthcare system. Patients with cardiomyopathy are at an increased risk of death and cardiovascular hospitalizations. In the present analysis, we examined the baseline characteristics and outcomes of black and white men and women with cardiomyopathy. All patients with cardiomyopathy (left ventricular ejection fraction (LVEF)50%) cared for at University of Pittsburgh Medical Center (UPMC) between 2011 and 2017 were included in this analysis. Patients were stratified by race, and outcomes were compared between Black and White patients using Cox proportional hazard models. Of a total of 18,003 cardiomyopathy patients, 15,804 were white (88%), 1,824 were black (10%) and 375 identified as other (2%). Over a median follow-up time of 3.4 years, 7,899 patients died. Black patients were on average a decade younger (p0.001) and demonstrated lower unadjusted all-cause mortality (hazard ratio [HR]: 0.83%; 95% CI 0.77 to 0.90; p0.001). However, after adjusting for age and other comorbidities, black patients had higher all-cause mortality compared to white patients (HR: 1.15, 95% CI 1.07 to 1.25; p0.001). These differences were seen in both men (HR:1.19, 95% CI 1.08 to 1.33; p0.001) and women (HR:1.12, 95% CI 0.99 to 1.25; p = 0.065). In conclusion, our data demonstrate higher all-cause mortality in black compared to white men and women with cardiomyopathy. These findings are likely explained, at least in part, by significantly higher rates of comorbidities in black patients. Earlier interventions targeting these comorbidities may mitigate the risk of progression to heart failure and improve outcomes.

The future of the American Board of Internal Medicine Maintenance of Certification (MOC) program is at a crossroads. The current MOC program lacks a clear visible mission, adds to modern health care’s onerous bureaucracy, and thus pulls physicians from the most important humanistic aspects of their profession. The aim of the MOC program should be to promote the best patient care by ensuring certified physicians maintain core skills through continuous education and evaluation. The program should focus on education and be designed with the rigorous obligations of practicing physicians in mind. Moving forward, the American Board of Internal Medicine should cocreate MOC with the physician community and apply innovative adult education techniques. Over time, data-driven methods and member feedback should be used to provide continuous program improvement. This review describes the origins of the current state of MOC, explores its evidence base, provides examples of model programs for the maintenance of complex professional skills, and outlines guiding principles for the future of MOC.

Background: The implantable cardioverter-defibrillator (ICD) is effective for preventing sudden death in patients with hypertrophic cardiomyopathy. However, data on performance and complications of implanted ICDs over particularly long time periods to inform clinical practice is presently incomplete. Methods: The study cohort comprises 217 consecutive hypertrophic cardiomyopathy patients with primary prevention ICDs implanted before 2008 and followed for ≥10 years (mean 12±4; range to 31). Results: Patients were 38±17 years at implant and 45 (21%) experienced appropriate interventions terminating ventricular tachycardia/ventricular fibrillation. The majority of ICD discharges occurred ≥5 years after implant (29 patients; 64%), including ≥10 years in 16 patients (36%). Initial device therapy increased in frequency from 2.3% of patients at P =0.005). Inappropriate ICD shocks in 39 patients occurred most commonly P =0.02). Other major device complications including infection and lead fractures and dislodgement occurred in 27 patients (12%) but did not increase in frequency over follow-up after implant ( P =0.47). There were no arrhythmic sudden death events among the 217 patients with ICD. Conclusions: In hypertrophic cardiomyopathy, after a primary prevention implant, ICD therapy often followed prolonged periods of device dormancy and increased progressively in frequency over time, including one-third of patients with initial therapy after 5 to 9 years, and an additional one-third of patients at ≥10 years. Frequency of inappropriate shocks decreased over follow-up, likely reflecting standard changes in device programming, while occurrence of device complications, such as lead fractures/infection, did not increase during follow-up.

Coronavirus disease 2019 (COVID-19) is a worldwide pandemic, and cardiovascular complications and arrhythmias in these patients are common. Cardiac monitoring is recommended for at risk patients; however, the availability of telemetry capable hospital beds is limited. We sought to evaluate a patch-based mobile telemetry system for inpatient cardiac monitoring during the pandemic.A prospective cohort study was performed of inpatients hospitalized during the pandemic who had mobile telemetry devices placed; patients were studied up until the time of discharge or death. The primary outcome was a composite of management changes based on data obtained from the system and detection of new arrhythmias. Other clinical outcomes and performance characteristics of the mobile telemetry system were studied.Eighty-two patients underwent mobile telemetry device placement, of which 31 (37.8%) met the primary outcome, which consisted of 24 (29.3%) with new arrhythmias detected and 18 (22.2%) with management changes. Twenty-one patients (25.6%) died during the study, but none from primary arrhythmias. In analyses, age and heart failure were associated with the primary outcome. Monitoring occurred for an average of 5.3 ± 3.4 days, with 432 total patient-days of monitoring performed; of these, QT-interval measurements were feasible in 400 (92.6%).A mobile telemetry system was successfully implemented for inpatient use during the COVID-19 pandemic and was shown to be useful to inform patient management, detect occult arrhythmias, and monitor the QT-interval. Patients with advanced age and structural heart disease may be more likely to benefit from this system.

His bundle pacing (HBP) has recently emerged as a technique to avoid the negative effects of long-term right ventricular apical pacing. In addition to providing physiologic ventricular activation, HBP has been shown to correct underlying conduction abnormalities in certain patients. Although large prospective, randomized clinical trials have not yet been completed, the available observational clinical data support the safety and efficacy of this technique. Here, we review the physiology of the his bundle (HB) as it relates to HBP, describe the current clinical experience, and discuss future directions of this emerging therapy.

Background: Atrial fibrillation (AF), the most common sustained arrhythmia in hypertrophic cardiomyopathy (HCM), is capable of producing symptoms that impact quality of life and is associated with risk for embolic stroke. However, the influence of AF on clinical course and outcome in HCM remains incompletely resolved. Methods: Records of 1558 consecutive patients followed at the Tufts Medical Center Hypertrophic Cardiomyopathy Institute for 4.8±3.4 years (from 2004 to 2014) were accessed. Results: Of the 1558 patients with HCM, 304 (20%) had episodes of AF, of which 226 (74%) were confined to symptomatic paroxysmal AF (average, 5±5; range, 1 to >20), whereas 78 (26%) developed permanent AF, preceded by 7±6 paroxysmal AF episodes. At last evaluation, 277 patients (91%) are alive at 62±13 years of age, including 89% in New York Heart Association class I or II. No difference was found in outcome measures for patients with AF and age- and sex-matched patients with HCM without AF. Four percent of patients with AF died of HCM-related causes (n=11), with annual mortality 0.7%; mortality directly attributable to AF (thromboembolism without prophylactic anticoagulation) was 0.1% per year (n=2 patients). Patients were treated with antiarrhythmic drugs (most commonly amiodarone [n=103] or sotalol [n=78]) and AF catheter ablation (n=49) or the Maze procedure at surgical myectomy (n=72). Freedom from AF recurrence at 1 year was 44% for ablation patients and 75% with the Maze procedure ( P P Conclusions: Transient symptomatic episodes of AF, often responsible for impaired quality of life, are unpredictable in frequency and timing, but amenable to effective contemporary treatments, and infrequently progress to permanent AF. AF is not a major contributor to heart failure morbidity or a cause of arrhythmic sudden death; when treated, it is associated with low disease-related mortality, no different than for patients without AF. AF is an uncommon primary cause of death in HCM virtually limited to embolic stroke, supporting a low threshold for initiating anticoagulation therapy.

Overt symptomatic atrial fibrillation (AF) occurs in over 20% of patients with hypertrophic cardiomyopathy (HC) leading to impaired quality of life, loss of productivity, and the risk for embolic stroke. However, the overall burden presented by AF in the HC population is unresolved due to the unknown frequency of silent asymptomatic episodes that do not necessarily achieve clinical recognition but nevertheless may have important disease-related implications. Therefore, stored electrograms were analyzed retrospectively for AF in 75 consecutive patients with HC (without AF history) implanted with dual-chamber cardioverter-defibrillators. Patients were followed for 5.0 ± 4.1 years at the Tufts Medical Center HCM Institute; ages were 50 ± 15 years, and 55% were male. Implantable cardioverter-defibrillator interrogation in the 75 patients showed AF to be absent in 54 (72%), 18 (24%) had clinically silent AF episodes, and the remaining 3 (4%) without previous asymptomatic episodes developed symptomatic and clinically overt paroxysmal AF. Of the 18 patients with clinically silent AF, 8 developed symptomatic AF, 4.1 ± 1.5 years later. Nonfatal embolic stroke occurred in 1 patient associated with asymptomatic AF and without other risk factors. In conclusion, clinically silent AF appears to be common in HC, occurring in almost 25% of patients. Such asymptomatic episodes of AF have important future implications, including potential thromboembolic risk, and development of symptomatic and clinically overt AF requiring prophylactic anticoagulation.

International audience; Arrhythmogenic cardiomyopathy (ACM) is an arrhythmogenic disorder of the myocardium not secondary to ischemic, hypertensive, or valvular heart disease. ACM incorporates a broad spectrum of genetic, systemic, infectious, and inflammatory disorders. This designation includes, but is not limited to, arrhythmogenic right/left ventricular cardiomyopathy, cardiac amyloidosis, sarcoidosis, Chagas disease, and left ventricular noncompaction. The ACM phenotype overlaps with other cardiomyopathies, particularly dilated cardiomyopathy with arrhythmia presentation that may be associated with ventricular dilatation and/or impaired systolic function. This expert consensus statement provides the clinician with guidance on evaluation and management of ACM and includes clinically relevant information on genetics and disease mechanisms. PICO questions were utilized to evaluate contemporary evidence and provide clinical guidance related to exercise in arrhythmogenic right ventricular cardiomyopathy. Recommendations were developed and approved by an expert writing group, after a systematic literature search with evidence tables, and discussion of their own clinical experience, to present the current knowledge in the field. Each recommendation is presented using the Class of Recommendation and Level of Evidence system formulated by the American College of Cardiology and the American Heart Association and is accompanied by references and explanatory text to provide essential context. The ongoing recognition of the genetic basis of ACM provides the opportunity to examine the diverse triggers and potential common pathway for the development of disease and arrhythmia.

Sudden cardiac death (SCD) secondary to sudden cardiac arrest (SCA) is a leading cause of death in the United States, claiming over a quarter million lives annually, and is directly responsible for 50% of all cardiovascular mortality. Brugada Syndrome (BrS) is an arrhythmogenic cardiovascular channelopathy that predisposes asymptomatic patients who have no identified disease to a high-risk of SCD/SCA as their first cardiac event/disease manifestation. Limited progress has been made in risk prediction of SCA and SCD, with the greatest challenge being the ability to identify the small high-risk subgroups concealed within the larger general population. In conclusion, accurate identification of high-risk asymptomatic BrS patients (through multiparametric risk scores composed of reliable and validated unambiguous clinical variables and biomarkers) may hold utility in improving current SCD prediction algorithms, and the appropriate primary prevention therapy may prove valuable in reducing risk of sudden death for this patient population. This systematic review aims to comprehensively summarize qualitative evidence that explore proposed clinical, electrocardiographic, electrophysiological, and genetic markers for risk stratification of patients with BrS phenotype, and to discuss the best available contemporary evidence regarding therapeutic approach.

International audience; Arrhythmogenic cardiomyopathy (ACM) is an arrhythmogenic disorder of the myocardium not secondary to ischemic, hypertensive, or valvular heart disease. ACM incorporates a broad spectrum of genetic, systemic, infectious, and inflammatory disorders. This designation includes, but is not limited to, arrhythmogenic right/left ventricular cardiomyopathy, cardiac amyloidosis, sarcoidosis, Chagas disease, and left ventricular noncompaction. The ACM phenotype overlaps with other cardiomyopathies, particularly dilated cardiomyopathy with arrhythmia presentation that may be associated with ventricular dilatation and/or impaired systolic function. This expert consensus statement provides the clinician with guidance on evaluation and management of ACM and includes clinically relevant information on genetics and disease mechanisms. PICO questions were utilized to evaluate contemporary evidence and provide clinical guidance related to exercise in arrhythmogenic right ventricular cardiomyopathy. Recommendations were developed and approved by an expert writing group, after a systematic literature search with evidence tables, and discussion of their own clinical experience, to present the current knowledge in the field. Each recommendation is presented using the Class of Recommendation and Level of Evidence system formulated by the American College of Cardiology and the American Heart Association and is accompanied by references and explanatory text to provide essential context. The ongoing recognition of the genetic basis of ACM provides the opportunity to examine the diverse triggers and potential common pathway for the development of disease and arrhythmia.

Background A dilemma arises about the merits of conservative management vs lead replacement and/or extraction when patients with a Medtronic Sprint Fidelis lead undergo generator replacement. Conflicting reports suggest that the fracture rate may increase after generator change. Objective The purpose of this study was to investigate the effect of generator replacement on Fidelis lead performance. Methods The Carelink PLUS cohort is composed of 21,500 Fidelis leads (model 6949) implanted in 1,006 centers. The survival rate for leads that remained active after the first generator replacement was compared with that for a control group with matched lead implant duration, patient age, patient sex, and generator type using the Kaplan-Meier method. The control group's starting point was adjusted to match the implant duration of each lead in the replacement group to allow for the comparison of similarly aged leads. Results Of the 2,988 implanted leads in each group, there was no statistical difference in the number of lead fractures between cases and controls (replacement, n=227; no replacement, n=257; Fisher exact, P = .169). Lead survival analysis demonstrated that lead performance since the first replacement procedure did not differ from that of the matched control group. Conclusion The Fidelis lead survival rate after generator replacement does not differ from that of the Fidelis leads that have not had replacement. In the event of generator replacement with no manifestation of lead fracture, the lead model, patient age and life expectancy, ejection fraction, comorbidities, ease of extraction, local extraction expertise, and patient preference should be considered to determine the best course of action.

The American College of Cardiology (ACC)/American Heart Association (AHA) clinical performance and quality measure sets serve as vehicles to accelerate translation of scientific evidence into clinical practice. Measure sets developed by the ACC/AHA are intended to provide practitioners and

The North American Thrombosis Forum Atrial Fibrillation Action Initiative consensus document is a comprehensive yet practical briefing document focusing on stroke and bleeding risk assessment in patients with atrial fibrillation, as well as recommendations regarding anticoagulation options and management. Despite the breadth of clinical trial data and guideline recommendation updates, many clinicians continue to struggle to synthesize the disparate information available. This problem slows the uptake and utilization of updated risk prediction tools and adoption of new oral anticoagulants. This document serves as a practical and educational reference for the entire medical community involved in the care of patients with atrial fibrillation.

Atrial fibrillation (AF) is the most common atrial arrhythmia in adults worldwide. As medical advancements continue to contribute to an ever-increasing aging population, the burden of atrial fibrillation on the modern health care system continues to increase. Therapies are also evolving, for treatment of the arrhythmia itself, and stroke risk mitigation. Internists and cardiologists alike are, in most instances, the frontline contact for AF patients, and would benefit from remaining facile in their understanding of care options. To continue to deliver high-quality care to this expanding patient group, an updated, concise review for the clinician is prudent. This article provides a comprehensive summary of the current epidemiology and pathophysiology of AF, as well as contemporary procedural therapeutic options.

The American Heart Association (AHA) commends the recently released Institute of Medicine (IOM) report, Strategies to Improve Cardiac Arrest Survival: A Time to Act (2015). The AHA recognizes the unique opportunity created by the report to meaningfully advance the objectives of improving outcomes for sudden cardiac arrest. For decades, the AHA has focused on the goal of reducing morbidity and mortality from cardiovascular disease though robust support of basic, translational, clinical, and population research. The AHA also has developed a rigorous process using the best available evidence to develop scientific, advisory, and guideline documents. These core activities of development and dissemination of scientific evidence have served as the foundation for a broad range of advocacy initiatives and programs that serve as a foundation for advancing the AHA and IOM goal of improving cardiac arrest outcomes. In response to the call to action in the IOM report, the AHA is announcing 4 new commitments to increase cardiac arrest survival: (1) The AHA will provide up to $5 million in funding over 5 years to incentivize resuscitation data interoperability; (2) the AHA will actively pursue philanthropic support for local and regional implementation opportunities to increase cardiac arrest survival by improving out-of-hospital and in-hospital systems of care; (3) the AHA will actively pursue philanthropic support to launch an AHA resuscitation research network; and (4) the AHA will cosponsor a National Cardiac Arrest Summit to facilitate the creation of a national cardiac arrest collaborative that will unify the field and identify common goals to improve survival. In addition to the AHA’s historic and ongoing commitment to improving cardiac arrest care and outcomes, these new initiatives are responsive to each of the IOM recommendations and demonstrate the AHA’s leadership in the field. However, successful implementation of the IOM recommendations will require a timely response by all stakeholders identified in the report and a coordinated approach to achieve our common goal of improved cardiac arrest outcomes.

Sudden death is a major problem, with significant impact on public health. Many conditions predispose to sudden cardiac death and sudden cardiac arrest (SCA), foremost among them coronary artery disease, and an effective therapy exists in the form of the implantable cardioverter defibrillator. Risk stratification for SCA remains imperfect, especially for patients with nonischemic cardiomyopathy. Ongoing trials may make it easier to identify those at high risk, and potentially those at very low risk, in the future.

This international consensus statement is the collaborative effort of three medical societies representing electrophysiology in North America, Europe, and Asian-Pacific area: the Heart Rhythm Society (HRS), the European Heart Rhythm Association (EHRA), and the Asia Pacific Heart Rhythm Society. The objective of the consensus document is to provide clinical guidance for diagnosis, risk stratification, and management of patients affected by inherited primary arrhythmia syndromes. It summarizes the opinion of the international writing group members based on their own experience and on a general review of the literature with respect to the clinical data on patients affected by channelopathies. This document does not address the indications of genetic testing in patients affected by inherited arrhythmias and their family members. Diagnostic, prognostic, and therapeutic implications of the results of genetic testing are also not included in this document because this topic has been covered by a recent publication1 coauthored by some of the contributors of this consensus document, and it remains the reference text on this topic. Guidance for the evaluation of patients with idiopathic ventricular fibrillation, sudden arrhythmic death …

We appreciated the interest of Barison and colleagues in our International Consensus Statement on the treatment of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D).1 Our document provided a comprehensive overview and recommendations for risk stratification and therapy of patients fulfilling the diagnostic criteria for ARVC/D. These criteria had been addressed by a previous International Task Force consensus document dedicated to diagnosis of ARVC/D.2 According to the revised criteria proposed by the International Task Force in 2010, the diagnosis of ARVC/D is based on the presence of major and minor criteria encompassing electrocardiographic, arrhythmic, morphological, histopathologic, and genetic factors. Diagnosis of definite ARVC/D is fulfilled in the presence of 2 major criteria or 1 major plus 2 minor or 4 minor criteria from different groups; the ARVC/D diagnosis is possible or borderline in the presence of insufficient criteria. In their Letter to the Editor, Barison and colleagues emphasized the valuable role of cardiac magnetic resonance (CMR) for diagnosis of ARVC/D, which relies on its ability to combine evaluation of ventricular size, function, and regional wall motion with characterization by late-gadolinium enhancement (LGE) of fibro-fatty myocardial scar, which is the hallmark lesion of ARVC/D. We totally agree that CMR is becoming the gold standard tool for detection of structural and functional ventricular abnormalities in ARVC/D. In the 2010 International Task Force consensus document, CMR was appropriately included among the diagnostic imaging techniques, and specific CMR reference values for normal (and abnormal) ventricular size, systolic function, and regional dyssynergy were provided. Tissue characterization by LGE was not included among these diagnostic criteria because of the potential risk of misdiagnosis of ARVC/D related to the difficulty of assessing LGE at the level of the thin right ventricular wall and possible confusion with normal epicardial fat tissue. More recently, the frequent involvement by the disease of the left ventricular wall in the form of epicardial-mediomural LGE has been recognized. As pointed out by the authors, LV LGE may enhance sensitivity for early/minor or predominant left variants of the ARVC/D; however, its diagnostic accuracy remains to be established. The prognostic role of CMR and, in particular, of postcontrast sequences for tissue characterization in patients with a diagnosis of definitive ARVC/D remains elusive. In our consensus statement on the treatment of ARVC/D, we performed a systematic review of outcome studies on ARVC/D available in the literature to identify predictor variables that were associated with an increased risk of major arrhythmic events (ie, sudden cardiac death, appropriate defibrillator interventions, or defibrillator therapy on fast ventricular tachycardia/ventricular fibrillation), nonsudden cardiac death, or heart transplantation in at least 1 published multivariable analysis. Although the predicting value of CMR for worse arrhythmic outcome was shown in the general population of patients showing premature ventricular beats with a left bundle branch morphology4 and in patients with suspected diagnosis of ARVC/D,5 no specific features of CMR, either alone or in combination, have been reported yet as independent predictors of life-threatening arrhythmic events in patients with a definite diagnosis of ARVC/D. This lack of evidence underscores the importance of undertaking future studies on this field.

Recent observations indicate that some hospital telemetry systems used for monitoring of patient heart rhythm have clinically significant latency, or delay between the real-time status of the patient and the ECG information displayed on the patient monitor. If these systems are used for clinical care that requires instantaneous monitoring, then patient safety may be compromised. The purpose of this advisory is to inform healthcare providers about this potential problem, clarify the intended use of the systems, detail measures to reduce risk, and recommend steps to manufacturers and stakeholders to minimize this problem in current and future telemetry systems. Wireless telemetry electrocardiographic monitoring is a cornerstone of hospital management for patients with cardiovascular conditions or at risk for cardiovascular conditions. Since the first transmission of an ECG by telephone wire by Willem Einthoven was reported in 1906,1,2 advances in signal processing and communications have led to rapid innovation in wireless communication for telemetry systems in acute care settings.3 The first wireless systems introduced in the 1970s were fairly simple in design. They transmitted analog telemetry signals using 1 dedicated frequency channel for each patient.4 In the 1980s, networked telemetry systems led to the creation of centralized telemetry viewing stations in intensive and acute care units. Starting in the 1990s, digital telemetry systems allowed for computerized signal recording, storage, and retrieval.5,6 As computing power increased, the networking capability of these systems increased, allowing for monitoring of electrocardiographic, hemodynamic, and other clinical data from multiple patients on a single networked system. By 2000, wireless communication in the hospital extended beyond telemetry systems, and the US Federal Communications Commission established a protected range of frequencies for wireless medical devices to minimize electromagnetic interference from other in-band radiofrequency sources.7,8 Today, networked wireless telemetry systems …

Implantation of implantable cardioverter defibrillators (ICDs) for primary prevention has been shown to significantly reduce mortality in several randomized controlled trials. However, many of these trials have excluded patients on hemodialysis as well as patients with advanced chronic kidney disease (CKD). Whether the benefits of ICD therapy extend to patients with CKD is not clear. This review will examine the relationship between advancing stage of CKD and risk/benefit of ICD placement. Furthermore, we will review the recent evidence for the rates of complications as CKD advances. The intent is to assist the clinician who is considering the risks and benefits of ICD implantation in patients who have significant competing comorbidities and have not been specifically studied in randomized controlled trials.

The ability to resuscitate cardiac arrest victims is a critical component of health-related topics in the athlete population. Even with screening, there will remain people who experience sudden cardiac arrest. An effective resuscitation strategy requires multiple elements, including planning for an event, appropriate team members who can provide cardiopulmonary resuscitation (CPR), rapid availability of automated external defibrillators (AEDs) and other appropriate equipment, and calls for emergency medical services (EMS). The chain of survival as articulated by the American Heart Association (AHA) calls for immediate recognition of cardiac arrest and activation of EMS, early CPR, rapid defibrillation, effective advanced life support, and integrated post–cardiac arrest care.1,2 Inadequacy in any one of these facets will reduce the chances of survival. AEDs are portable devices capable of detecting and terminating ventricular tachycardia and fibrillation. All require human input to place the pads and turn on the device. Some are fully automated in that they will analyze the rhythm and provide a shock if the arrhythmia is deemed shockable. However, most are semiautomated in that they require continued human input, including activation to analyze the rhythm, and then if the arrhythmia is deemed shockable, further activation to shock. Ease of use has been demonstrated for both automated and semiautomated AEDs. AEDs are manufactured by many companies, with subtle differences in sensing algorithms and shock energy. The sensitivity and specificity of AEDs are excellent and likely better than human analysis of arrhythmias.3 In arrhythmia libraries, the sensitivity of most devices approaches 100%, as does the specificity.3 Whether one manufacturer’s algorithms are more accurate than others is not clear. Some devices will correct for CPR artifact, analyze the quality of the CPR, or both. Nearly all current AEDs incorporate biphasic waveforms; however, the specifics of the waveform and the energy vary …

Sudden cardiac death in a young athlete is a tragic and high-profile event. The best way to prevent such deaths is, however, highly debated. The Italian experience informed the European recommendation for the inclusion of a 12-lead ECG in screening tests for all athletes.1,2 Although American authors have acknowledged the possible benefits of such an approach, many have expressed concern over the portability of such a model to the US healthcare system. Concern has focused in particular on the idea of mandatory testing, cost effectiveness, the availability of practitioners qualified to interpret ECGs, and the burden of false-positive results. With professional sports organizations such as the International Olympic Committee, the National Basketball Association, the National Football League, and the Union of European Football Associations endorsing or implementing screening programs for their athletes, with a recent analysis suggesting a degree of cost effectiveness in line with other accepted medical interventions,3 and with the American Heart Association offering a cautious endorsement to the idea of local programs,4 volunteer-led testing programs across the US have begun to emerge. Thus, although no detailed guidance for the interpretation of the athlete's ECG exists, many physicians will be called on to interpret an athlete's ECG. Editorial see p 669 A principal obstacle to such interpretation is the difficulty in distinguishing abnormal patterns from physiological effects of training. Many clinical and ECG findings that may be a cause of concern in the general population are normal for athletes. In addition, the test characteristics of the ECG for different findings vary according to age, sex, ethnicity, sport, and level of training. In particular, different challenges exist for younger athletes because of the evolution of the ECG with age. This is further complicated by historical …

Case presentation : A 61-year-old moderately obese (body mass index 28.1 kg/m2) hypertensive diabetic man without any prior cardiac history collapsed suddenly at a town meeting. Bystander cardiopulmonary resuscitation was initiated, an automated external defibrillator available at the town hall was deployed, and a single shock was delivered. He regained a pulse and spontaneous respirations. He was transported to the local hospital, where he was stabilized, but remained comatose. The patient was immediately transferred to a tertiary hospital, where a therapeutic hypothermia protocol was initiated. No ECG or laboratory evidence of a transmural myocardial infarction (MI) was present. He regained consciousness 2 days after resuscitation. Coronary angiography demonstrated significant obstruction of 3 major coronary arteries, with mild global impairment of left ventricular function with an ejection fraction of 45%. Coronary bypass surgery was performed, and after implantable cardioverter-defibrillator (ICD) placement, he was discharged on a statin, a β-blocker, aspirin, and an angiotensin-converting enzyme inhibitor. The patient has no residual neurological or cognitive deficits. He has done well clinically in a cardiac rehabilitation program stressing exercise, diet, and lifestyle changes to achieve an ideal body weight. Sudden cardiac death (SCD) from cardiac arrest is the most common cause of death worldwide, accounting for >50% of all deaths from cardiovascular disease.1–4 SCD results in ≈250 000 to 300 000 deaths annually in the United States,1–4 and is characterized by unexpected cardiovascular collapse due to an underlying cardiovascular cause.1,2 SCD represents a major challenge for the clinician because most episodes occur in individuals without previously known cardiac disease.1–4 Because most individuals experiencing SCD currently are not identifiable as being at high risk, community-based public access to defibrillation programs is essential to save lives and improve neurological and functional outcomes for …

Evidence-based medicine has provided the foundation for refinement of the guideline development process and the emergence of the disciplines of measuring quality, performance, and outcomes. With implementation of electronic medical records as part of healthcare reform, multiple aspects of these disciplines will be incorporated into clinical cardiac electrophysiology. Performance measures and quality metrics will assume an influential role in the management of patients with heart rhythm disturbances in the near future.

In 1962, Thomas Kuhn popularized the term “paradigmshift” to describe a fundamental change in scientificassumptions in his book entitled “The Structure ofScientific Revolutions” [1]. While some would argue thatthe term has been overused, most would agree thatrevolutionary moments that fundamentally alter our under-standing of a condition merit this designation. Someconsider such a “paradigm shift” to have occurred inthe field of cardiac electrophysiology in 1998 withHaissaguerre’s publication in The New England Journal ofMedicine on “Spontaneous Initiation of Atrial Fibrillationby Ectopic Beats Originating in the Pulmonary Veins” [2].Over a decade later, the medical community has embracedthis mechanistic insight that the triggers of atrial fibrillation(AF) are often found in the pulmonary veins. As a result,we have added AF ablation procedures to our therapeuticarmamentarium in an effort to cure this arrhythmia. Due tothe heterogeneous nature of AF, involving multiple triggersand substrates which range from structurally normal heartsto complex congenital and acquired abnormalities, ourmechanistic knowledge remains rudimentary. While weremain in the infancy of our understanding of thisextraordinary common, yet challenging, arrhythmia, weare on the threshold of innovative ablation techniques,multiple novel antiarrhythmic agents, and alternatives tovitamin K antagonists with the emergence of directthrombin and factor Xa inhibitors [3–5]. Each has thepotential to fundamentally alter the clinical strategiestraditionally employed for restoration of normal sinusrhythm and prevention of thromboembolic events. In thisrespect, it is appropriate to evaluate these emergingtherapies and their potential impact on therapeutic strategiesfor AF over the next several years.While most of the clinical experience with AF ablationhas been with thermal lesions from radiofrequency energy,new energy sources are emerging that have the potential toimprove outcomes in AF patients. The emergence of coldas a therapeutic modality can be traced to James Arnott, awell known British physician (1797–1883). Only in recentyears, however, with the development of an over-the-wire,deflectable, balloon-based catheter design has the potentialfor the delivery of cryoenergy in the treatment of AFbecome a reality. The novelty lays not only in the energysource, cryothermal energy, rather than conventionalradiofrequency energy, but also in the approach to lesionssets, single and circumferential, as opposed to traditionalpoint-by-point ablation. A balloon-based delivery platformmay provide a more efficient means of achieving pulmo-nary vein isolation, particularly suited for patients withparoxysmal AF in whom the goal is to abolish triggers.Thus far, several European centers have demonstratedprocedure safety and short-term efficacy, achieving sinusrhythm in 74% of patients with paroxysmal AF without theuse of antiarrhythmic drug therapy [3]. The major compli-cation appears to be phrenic nerve palsy with ablation ofthe right-sided veins, whereas no significant pulmonaryvein stenosis has been noted [3, 6]. Further advances indevice configurations will likely address the issues ofvariable anatomy, and hybrid approaches will be necessaryto ablate the substrate in patients with persistent AF.Direct clinical comparisons between radiofrequency andcryoablation will expectedly follow.