The future of long-term monitoring after catheter and surgical ablation for atrial fibrillation.

In recent years, there has been an emergence of long-term cardiac monitoring devices, particularly as they relate to nonprescribed, user-initiated, wearable- and/or, smartphone-based devices. With these new available data, practitioners are challenged to interpret these data in the context of routine clinical decision-making. While there are many potential uses for long-term rhythm monitoring, in this review, we will focus on the evolving role of this technology in atrial fibrillation (AF) monitoring after catheter and/or surgical ablation. Here, we explore the landscape of prescription-based tools for long-term rhythm monitoring; investigate commercially available technologies that are accessible directly to patients, and look towards the future with investigative technologies that could have a growing role in this space.

Genetically based atrial fibrillation: Current considerations for diagnosis and management.

Atrial fibrillation (AF) is the most common atrial arrhythmia and is subcategorized into numerous clinical phenotypes. Given its heterogeneity, investigations into the genetic mechanisms underlying AF have been pursued in recent decades, with predominant analyses focusing on early onset or lone AF. Linkage analyses, genome-wide association studies (GWAS), and single gene analyses have led to the identification of rare and common genetic variants associated with AF risk. Significant overlap with genetic variants implicated in dilated cardiomyopathy syndromes, including truncating variants of the sarcomere protein titin, have been identified through these analyses, in addition to other genes associated with cardiac structure and function. Despite this, widespread utilization of genetic testing in AF remains hindered by the unclear impact of genetic risk identification on clinical outcomes and the high prevalence of variants of unknown significance (VUS). However, genetic testing is a reasonable option for patients with early onset AF and in those with significant family history of arrhythmia. While many knowledge gaps remain, emerging data support genotyping to inform selection of AF therapeutics. In this review, we highlight the current understanding of the complex genetic basis of AF and explore the overlap of AF with inherited cardiomyopathy syndromes. We propose a set of criteria for clinical genetic testing in AF patients and outline future steps for the integration of genetics into AF care.

Mobile Health for Arrhythmia Diagnosis and Management.

Palpitations are a common symptom managed by general practitioners and cardiologists; atrial fibrillation (AF) is the most common arrhythmia in adults. The recent commercial availability of smartphone-based devices and wearable technologies with arrhythmia detection capabilities has revolutionized the diagnosis and management of these common medical issues, as it has placed the power of arrhythmia detection into the hands of the patient. Numerous mobile health (mHealth) devices that can detect, record, and automatically interpret irregularities in heart rhythm and abrupt changes in heart rate using photoplethysmography (PPG)- and electrocardiogram-based technologies are now commercially available. As opposed to prescription-based external rhythm monitoring approaches, these devices are more inexpensive and allow for longer-term monitoring, thus increasing sensitivity for arrhythmia detection, particularly for patients with infrequent symptoms possibly due to cardiac arrhythmias. These devices can be used to correlate symptoms with cardiac arrhythmias, assess efficacy and toxicities of arrhythmia therapies, and screen the population for serious rhythm disturbances such as AF. Although several devices have received clearance for AF detection from the United States Food & Drug Administration, limitations include the need for ECG confirmation for arrhythmias detected by PPG alone, false positives, false negatives, charging requirements for the battery, and financial cost. In summary, the growth of commercially available devices for remote, patient-facing rhythm monitoring represents an exciting new opportunity in the care of patients with palpitations and known or suspected dysrhythmias. Physicians should be familiar with the evidence that underlies their added value to patient care and, importantly, their current limitations.

Physiologic lead placement with electroanatomic mapping: A case series.

INTRODUCTION: His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) have emerged as attractive alternatives to traditional biventricular pacing to achieve cardiac resynchronization therapy. Early reported results have been inconsistent, particularly amongst patients in whom initial placement with traditional approaches has been unsuccessful or those with complex anatomy or congenital abnormalities. In this report, we describe the use of three-dimensional electroanatomic mapping (EAM) in five selected cases. METHODS: Five patients from multiple clinical sites underwent EAM-guided HBP or LBBAP by highly trained electrophysiologists with significant experience with conduction system pacing. Each patient in this series underwent EAM-guided conduction system pacing due to complex anatomy and/or prior failed lead implantation. RESULTS: EAM-guided lead implantation was successful in all five cases. Capture thresholds were relatively low and patients continued to have evidence of successful lead implantation with minimum 1-month follow-up. The fluoroscopy time varied, likely owing to the variable complexity of the cases. CONCLUSIONS: The use of EAM, in combination with traditional intracardiac electrograms with or without fluoroscopy, allows more targeted and precise placement of leads for HBP and LBBAP pacing. Further investigation is needed to determine this strategy's long-term performance and to optimize patient selection.

Atrial fibrillation and atrial cardiomyopathies.

Atrial fibrillation (AF) is the most common arrhythmia among adults. While there have been incredible advances in the management of AF and its clinical sequelae, investigation of atrial cardiomyopathies (ACMs) is becoming increasingly more prominent. ACM refers to the electromechanical changes-appreciated subclinically and/or clinically-that underlie atrial dysfunction and create an environment ripe for the development of clinically apparent AF. There are several subtypes of ACM, distinguished by histologic features. Recent progress in cardiovascular imaging, including echocardiography with speckle-tracking (e.g., strain analysis), cardiovascular magnetic resonance imaging (CMR), and atrial 4-D flow CMR, has enabled increased recognition of ACM. Identification of ACM and its features carry clinical implications, including elevating a patient's risk for development of AF, as well as associations with outcomes related to catheter-based and surgical AF ablation. In this review, we explore the definition and classifications of ACM, its complex relationship with clinical AF, imaging modalities, and clinical implications. We propose next steps for a more unified approach to ACM recognition that can direct further research into this complex field.

Primary Prevention Implantable Cardioverter-Defibrillator Therapy in Heart Failure with Recovered Ejection Fraction.

Given recent advances in both pharmacologic and nonpharmacologic strategies for improving outcomes related to chronic systolic heart failure, heart failure with recovered ejection fraction (HFrecEF) is now recognized as a distinct clinical entity with increasing prevalence. In many patients who once had an indication for active implantable cardioverter-defibrillator (ICD) therapy, questions remain regarding the usefulness of this primary prevention strategy to protect against syncope and cardiac arrest after they have achieved myocardial recovery. Early, small studies provide convincing evidence for continued guideline-directed medical therapy (GDMT) in segments of the HFrecEF population to promote persistent left ventricular myocardial recovery. Retrospective data suggest that the risk of sudden cardiac death is lower, but still present, in HFrecEF as compared with HF with reduced ejection fraction, with reports of up to 5 appropriate ICD therapies delivered per 100 patient-years. The usefulness of continued ICD therapy is weighed against the unfavorable effects of this strategy, which include a cumulative risk of infection, inappropriate discharge, and patient-level anxiety. Historically, many surrogate measures for risk stratification have been explored, but few have demonstrated efficacy and widespread availability. We found that the available data to inform decisions surrounding the continued use of active ICD therapies in this population are incomplete, and more advanced tools such as genetic testing, evaluation of high-risk structural cardiomyopathies (such as noncompaction), and cardiac magnetic resonance imaging have emerged as vital in risk stratification. Clinicians and patients should engage in shared decision-making to evaluate the appropriateness of active ICD therapy for any given individual. In this article, we explore the definition of HFrecEF, data underlying continuation of guideline-directed medical therapy in patients who have achieved left ventricular ejection fraction recovery, the benefits and risks of active ICD therapy, and surrogate measures that may have a role in risk stratification.

Management of systemic fungal infections in the presence of a cardiac implantable electronic device: A systematic review.

Evidence to inform the management of systemic fungal infections in the setting of a cardiac implantable electronic devices (CIED), such as a permanent pacemaker or implantable cardioverter-defibrillator, is scant and limited to case reports and series. The available literature suggests high morbidity and mortality. To better characterize the shared experience of these cases and their outcomes, we performed a systematic review. We investigated all published reports of systemic fungal infections-fungemia and fungal vegetative disease-in the context of CIED, drawing from PubMed, EMBASE, and the Cochrane database of systematic reviews, inclusive of patients who received treatment between January 2000 and May 2020. Exclusion criteria included presence of ventricular assist device and concurrent bacteremia, bacterial endocarditis, bacterial vegetative infection, or viremia. Among 6261 screened articles, 48 cases from 41 individual studies were identified. Candida and Aspergillus species were the most commonly isolated fungi. There was significant heterogeneity in antifungal medication selection and duration. CIED extraction-either transvenous or surgical-was associated with increased survival to hospital discharge (92%) and clinical recovery at latest follow-up (81%), compared to cases where CIED extraction was deferred (56% and 40%, respectively). Importantly, there were no prospective data, and the data were limited to individual case reports and one small case series. In summary, CIED extraction is associated with improved fungal clearance and patient survival. Reported antifungal regimens are heterogeneous and nonuniform. Prospective studies are needed to verify these results and define optimal antifungal regimens.

Primary prevention with the implantable cardioverter-defibrillator in high-risk long-QT syndrome patients.

AIMS: Prospective data regarding the role of implantable cardioverter-defibrillator (ICD) for the primary prevention of sudden cardiac death in patients with long QT syndrome (LQTS) is scarce. Herein, we explore the prospective Rochester LQTS ICD registry to assess the risk for appropriate shock in primary prevention in a real-world setting. METHODS AND RESULTS: We studied 212 LQTS patients that had ICD implantation for primary prevention. Best-subsets proportional-hazards regression analysis was used to identify clinical variables that were associated with the first appropriate shock. Conditional models of Prentice, Williams, and Peterson were utilized for the analysis of recurrent appropriate shocks. During a median follow-up of 9.2 ± 4.9 years, there were 42 patients who experienced at least one appropriate shock and the cumulative probability of appropriate shock at 8 years was 22%. QTc ≥ 550 ms [hazard ratio (HR) 3.94, confidence interval (CI) 2.08-7.46; P < 0.001) and prior syncope on ß-blockers (HR 1.92, CI 1.01-3.65; P = 0.047) were associated with increased risk of appropriate shock. History of syncope while on ß-blocker treatment (HR 1.87, CI 1.28-2.72; P = 0.001), QTc 500-549 ms (HR 1.68, CI 1.10-2.81; P = 0.048), and QTc ≥ 550 ms (HR 3.66, CI 2.34-5.72; P < 0.001) were associated with increased risk for recurrent appropriate shocks, while ß-blockers were not protective (HR 1.03, CI 0.63-1.68, P = 0.917). LQT2 (HR 2.10, CI 1.22-3.61; P = 0.008) and multiple mutations (HR 2.87, CI 1.49-5.53; P = 0.002) were associated with higher risk for recurrent shocks as compared with LQT1. CONCLUSION: In this prospective ICD registry, we identified clinical and genetic variables that were associated appropriate shock risk. These data can be used for risk stratification in high-risk patients evaluated for primary prevention with ICD.

Patient characteristics as predictors of recurrence of atrial fibrillation following cryoballoon ablation.

BACKGROUND: While several studies have evaluated predictors for atrial fibrillation (AF) recurrence following catheter ablation, there are limited data specific to cryoballoon ablation (CBA). METHODS: We analyzed a prospective registry of patients at a single institution who underwent CBA. Recurrence of AF (RAF) was defined as recurrence of AF by 12-month follow-up, excluding the 3-month blanking period. Univariate analysis was performed to evaluate predictors of RAF. Receiver operating characteristic analysis was used to compare and evaluate the performance of various risk scores for discriminating risk of RAF. RESULTS: There were 542 patients included in the analysis with mean age 61.3 ± 10.6 years, 67.9% male, and 51.6% paroxysmal AF (PAF). Overall, only left atrial diameter (LAD) > 40 mm and ERAF (early recurrence of AF within 0-3 month blanking period) were significant predictors of RAF. In the PAF specific subgroup, LAD > 40 mm, AF duration > 12 months, prior stroke or transient ischemic attack, ERAF, and having previously failed an antiarrhythmic drug were significant predictors of RAF. In persistent AF (PeAF) subgroup, obstructive sleep apnea (OSA) and ERAF were significant predictors of RAF. Out of clinical risk scores tested, BASEAF2 had the highest performance with area under the curve of 0.646 (95% confidence interval [0.548, 0.708]; P < .01). CONCLUSIONS: In this single-center retrospective study of CBA, we found only LAD > 40 mm and ERAF to be predictors of RAF. We identified OSA as a potential targetable risk factor in PeAF patients undergoing CBA. Out of risk scores tested for discriminating risk of RAF, BASEAF2 had the best performance.

Baseline adverse electrical remodeling and the risk for ventricular arrhythmia in Cardiac Resynchronization Therapy Recipients (MADIT CRT).

INTRODUCTION: Adverse electrical remodeling (AER), represented here as the sum absolute QRST integral (SAI QRST), has previously been shown to be directly associated with the risk for ventricular arrhythmia (VA). Cardiac resynchronization therapy (CRT) is known to reduce the risk for VA through various mechanisms, including reverse remodeling, and we aimed to evaluate the association between baseline AER and the risk for VA in CRT recipients. METHODS AND RESULTS: The study population comprised 961 CRT-D implanted patients from the MADIT CRT study. The relationship between SAI QRST, VA risk, and VA risk/death was evaluated as a continuous and as a categorical variable-tertiles (T1 ≤ 0.527, T2 0.528-0.766, T3 > 0.766). In a multivariable model, AER was inversely associated with the risk of VA. Each unit increase in SAI QRST was associated with 64% (P  =  0.007) and 54% (P  =  0.003) decrease in the risk of VA and VA/death, respectively. Patients with high SAI QRST (T3) and medium SAI QRST (T2) had 52% (P < 0.001) and 32% (P  =  0.027) reduced risk for VA and 44% (P  =  0.002) and 26% (P  =  0.055) reduced risk for VA/death as compared with patients with low SAI QRST (T1), respectively. CONCLUSION: In CRT implanted patients with mild heart failure, baseline AER was inversely associated with the risk for VA and VA/death; this is a finding that contradicts the relationship previously reported in non-CRT implanted patients. We theorize that CRT may abate the process of AER; however, characterization of this mechanism requires further study.

Percutaneous left atrial appendage occlusion in the prevention of stroke in atrial fibrillation: a systematic review.

Atrial fibrillation is commonly coexistent with heart failure, and the management of the heart failure patient would be incomplete without an appreciation for atrial fibrillation management. There are many complications associated with oral anticoagulation in the prevention of stroke related to atrial fibrillation. In recent years, the advent of several percutaneous left atrial appendage (LAA) occlusion/closure strategies has sought to provide an alternative treatment modality. Here, we systematically review the published literature to investigate the efficacy and safety of percutaneous LAA occlusion/closure devices. We searched PubMed, EMBASE, Cochrane database of systematic reviews, and the FDA Medical Devices database. Using prespecified criteria, we identified studies of the Amplatzer Cardiac Plug (St. Jude Medical), Amplatzer Amulet (St. Jude Medical), Lariat suture delivery device (SentreHeart), and Watchman device (Boston Scientific). We analyzed 2 randomized controlled trials (RCT) and 15 non-randomized registries that satisfied the study criteria. The two RCT both studied the Watchman device versus standard warfarin therapy; the studies indicate that the Watchman may be non-inferior to warfarin. Long-term efficacy outcomes for the Watchman device are promising. Data regarding the Amplatzer Cardiac Plug, Amplatzer Amulet, and Lariat suture delivery device are limited by the paucity of RCT data. High-quality prospective research is needed to directly compare LAA occlusion/closure strategies against one another as well as versus the direct oral anticoagulation medications. Data regarding the role of LAA occlusion in the heart failure population are lacking.

What Is Aortic Dissection?

This JAMA Patient Page describes aortic dissection, a tear in the aorta, and how it is diagnosed and treated.

What Is an Abdominal Aortic Aneurysm?

This JAMA Patient Page describes abdominal aortic aneurysms and their symptoms, risk factors, diagnosis, and treatment.

Roles and indications for use of implantable defibrillator and resynchronization therapy in the prevention of sudden cardiac death in heart failure.

Implantable devices are indicated in the primary and secondary prevention of potentially life-threatening ventricular tachyarrhythmias in patients with heart failure. Early studies, including the landmark MADIT trials, showed that implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy (CRT) devices can play a significant role in aborting and preventing ventricular arrhythmias, respectively, that can cause sudden cardiac death. To this day, there have been a number of randomized controlled trials, with respective substudy analyses, that have attempted to better understand the indications for these interventions in patient care. Here, we summarize the major results of these studies, and we discuss the role of ICD therapy for both ischemic and non-ischemic cardiomyopathy, emerging evidence in support of wearable defibrillators, and the impact of modified ICD programming strategies on patient outcomes. Regarding CRT therapy, the phenomenon of ventricular reverse remodeling is an important prognostic indicator in preventing future ventricular tachyarrhythmia episodes. In summation, we provide an overview of the possible selection criteria that can be used in identifying appropriate patients for ICD and/or CRT therapy, as supported by the data.

Coping with a Terminal Diagnosis: Perspectives from Inside the Patient's Home.

This vignette describes the evolving and intimate relationship between a medical student and his patient, and their shared journey in accepting the patient's terminal diagnosis. The news of her diagnosis touched all parts of her life, and this account explores those effects on a very personal level.

The Influenza A PB1-F2 and N40 Start Codons Are Contained within an RNA Pseudoknot.

Influenza A is a negative-sense RNA virus with an eight-segment genome. Some segments encode more than one polypeptide product, but how the virus accesses alternate internal open reading frames (ORFs) is not completely understood. In segment 2, ribosomal scanning produces two internal ORFs, PB1-F2 and N40. Here, chemical mapping reveals a Mg(2+)-dependent pseudoknot structure that includes the PB1-F2 and N40 start codons. The results suggest that interactions of the ribosome with the pseudoknot may affect the level of translation for PB1-F2 and N40.