Pulsed Field Ablation: A Comprehensive Update.

One of the recent advancements in the field of cardiac electrophysiology is pulsed field ablation (PFA). PFA is a novel energy modality that does not rely on thermal processes to achieve ablation which, in turn, results in limited collateral damage to surrounding structures. In this review, we discuss the mechanisms, safety, efficacy, and clinical applications of PFA for the management of atrial and ventricular arrhythmias. We also summarize the published pre-clinical and clinical studies regarding this new technology.

Left bundle branch pacing vs ventricular septal pacing for cardiac resynchronization therapy.

Background: The outcomes of left bundle branch pacing (LBBP) and left ventricular septal pacing (LVSP) in patients with heart failure remain to be learned. Objective: The objective of this study was to assess the echocardiographic and clinical outcomes of LBBP, LVSP, and deep septal pacing (DSP). Methods: This retrospective study included patients who met the criteria for cardiac resynchronization therapy (CRT) and underwent attempted LBBP in 5 Mayo centers. Clinical, electrocardiographic, and echocardiographic data were collected at baseline and follow-up. Results: A total of 91 consecutive patients were included in the study. A total of 52 patients had LBBP, 25 had LVSP, and 14 had DSP. The median follow-up duration was 307 (interquartile range 208, 508) days. There was significant left ventricular ejection fraction (LVEF) improvement in the LBBP and LVSP groups (from 35.9 ± 8.5% to 46.9 ± 10.0%, P < .001 in the LBBP group; from 33.1 ± 7.5% to 41.8 ± 10.8%, P < .001 in the LVSP group) but not in the DSP group. A unipolar paced right bundle branch block morphology during the procedure in lead V1 was associated with higher odds of CRT response. There was no significant difference in heart failure hospitalization and all-cause deaths between the LBBP and LVSP groups. The rate of heart failure hospitalization and all-cause deaths were increased in the DSP group compared with the LBBP group (hazard ratio 5.10, 95% confidence interval 1.14-22.78, P = .033; and hazard ratio 7.83, 95% confidence interval 1.38-44.32, P = .020, respectively). Conclusion: In patients undergoing CRT, LVSP had comparable CRT outcomes compared with LBBP.

Sex Disparities in Cardiovascular Disease.

Cardiovascular disease is the leading cause of death in women. It remains underdiagnosed, undertreated, and portends worse outcomes in women than men. Disparities exist in every stage of science, from bench research to the editorial board of major journals and in every cardiovascular subspecialty. This review summarizes differences in cardiovascular risk factors and disparities in management and outcomes of ischemic heart disease, heart failure, aortic stenosis, and atrial fibrillation. It also provides an overview of female representation as participants and leaders of clinical trials, editorial boards, and academic institutions. Strategies to overcome these disparities are proposed with examples of successful programs.

Cardiac implantable electronic devices in female patients: Esthetic, breast implant, and anatomic considerations.

INTRODUCTION: The implantation of a cardiac implantable electronic device (CIED) can have esthetic and psychological consequences on patients. We explore a heart team model for care coordination and discuss esthetic approaches for improved cosmetic outcomes in patients undergoing (CIED)-related procedures or de novo implantation. METHODS: Patients undergoing CIED surgery for approved indications between June 2015 and June 2022 were identified. Patients were included when surgical care was provided by a collaborative relationship between the primary electrophysiologist and the plastic surgeon. Patient demographics, details of the surgical procedure, information on breast implants, complications, and outcomes related to cosmesis were recorded. RESULTS: Twenty-two female patients were included in this study. The mean age was 50.2 ± 18.2 years. The mean follow-up duration was 2.2 ± 5.5 months. The top two indications for the procedure included CIED generator change (n = 9, 41%) and implantable cardioverter-defibrillator (ICD) implantation (n = 7, 32%). The most common reasons for involving plastic surgery in the procedure included surgery near breast implants (n = 10, 45%) and device displacement or discomfort (n = 8, 36%). CIED pocket position was prepectoral in 10 cases (45%), subpectoral in 11 patients (50%), and intramuscular in one patient (4.5%). The majority of the patients (20, 91%) had cosmetically acceptable results postprocedure. One patient (4.5%) had breast asymmetry on the CIED side, and another continued to have skin erosion over the CIED and leads. CONCLUSION: A heart team approach incorporating the expertize of cardiac electrophysiology and plastic surgery is essential for providing optimal care for patients with breast implants and patients requesting esthetic appeal.

Exposing influence campaigns in the age of LLMs: a behavioral-based AI approach to detecting state-sponsored trolls.

The detection of state-sponsored trolls operating in influence campaigns on social media is a critical and unsolved challenge for the research community, which has significant implications beyond the online realm. To address this challenge, we propose a new AI-based solution that identifies troll accounts solely through behavioral cues associated with their sequences of sharing activity, encompassing both their actions and the feedback they receive from others. Our approach does not incorporate any textual content shared and consists of two steps: First, we leverage an LSTM-based classifier to determine whether account sequences belong to a state-sponsored troll or an organic, legitimate user. Second, we employ the classified sequences to calculate a metric named the "Troll Score", quantifying the degree to which an account exhibits troll-like behavior. To assess the effectiveness of our method, we examine its performance in the context of the 2016 Russian interference campaign during the U.S. Presidential election. Our experiments yield compelling results, demonstrating that our approach can identify account sequences with an AUC close to 99% and accurately differentiate between Russian trolls and organic users with an AUC of 91%. Notably, our behavioral-based approach holds a significant advantage in the ever-evolving landscape, where textual and linguistic properties can be easily mimicked by Large Language Models (LLMs): In contrast to existing language-based techniques, it relies on more challenging-to-replicate behavioral cues, ensuring greater resilience in identifying influence campaigns, especially given the potential increase in the usage of LLMs for generating inauthentic content. Finally, we assessed the generalizability of our solution to various entities driving different information operations and found promising results that will guide future research.

Cardiac Resynchronisation with Conduction System Pacing.

To date, biventricular pacing (BiVP) has been the standard pacing modality for cardiac resynchronisation therapy. However, it is non-physiological, with the activation spreading between the left ventricular epicardium and right ventricular endocardium. Up to one-third of patients with heart failure who are eligible for cardiac resynchronisation therapy do not derive benefit from BiVP. Conduction system pacing (CSP), which includes His bundle pacing and left bundle branch area pacing, has emerged as an alternative to BiVP for cardiac resynchronisation. There is mounting evidence supporting the benefits of CSP in achieving synchronous ventricular activation and repolarisation. The aim of this review is to summarise the current options and outcomes of CSP when used for cardiac resynchronisation in patients with heart failure.

Catheter ablation of atrial fibrillation in patients with and without hypertrophic cardiomyopathy: systematic review and meta-analysis.

BACKGROUND: Atrial fibrillation (AF) is common in hypertrophic cardiomyopathy (HCM). There is limited data regarding the outcomes of AF catheter ablation in HCM patients. In this study, we aimed to synthesize all available evidence on the effectiveness of ablation of AF in patients with HCM compared to those without HCM. METHODS AND RESULTS: We systematically reviewed bibliographic databases to identify studies published through February 2023. We included cohort studies with available quantitative information on rates of recurrent atrial arrhythmias, anti-arrhythmic drug (AAD) therapy, and repeat ablation procedures after initial AF ablation in patients with vs without HCM. Estimates were combined using random-effects meta-analysis models and reported as risk ratios (RR) and 95% confidence intervals (CI). Eight studies were included in quantitative synthesis (262 HCM and 642 non-HCM patients). During median follow-up 13-54 months across studies, AF recurrence rates ranged from 13.3% to 92.9% in HCM and 7.6% to 58.8% in non-HCM patients. The pooled RR for recurrent atrial arrhythmia after the first AF ablation in HCM patients compared to non-HCM controls was 1.498 (95% CI = 1.305-1.720; P < 0.001). During follow-up, HCM patients more often required AAD therapy (RR = 2.844; 95% CI = 1.713-4.856; P < 0.001) and repeat AF ablation (RR = 1.544; 95% CI = 1.070-2.228; P = 0.02). The pooled RR for recurrent atrial arrhythmias after the last AF ablation was higher in patients with HCM than those without HCM (RR = 1.607; 95% CI = 1.235-2.090; P < 0.001). CONCLUSIONS: Compared to non-HCM patients, those with HCM had higher rates of recurrent atrial arrhythmias, AAD use, and need for repeat AF ablation after initial ablation of AF.

Anatomy and Pathology of the Cardiac Conduction System.

The cardiac conduction system is formed of histologically and electrophysiologically distinct specialized tissues uniquely located in the human heart. Understanding the anatomy and pathology of the cardiac conduction system is imperative to an interventional electrophysiologist to perform safe ablation and device therapy for the management of cardiac arrhythmias and heart failure. The current review summarizes the normal and developmental anatomy of the cardiac conduction system, its variation in the normal heart and congenital anomalies, and its pathology and discusses important clinical pearls for the proceduralist.

Outcomes of conduction system pacing for cardiac resynchronization therapy in patients with heart failure: A multicenter experience.

BACKGROUND: Whether conduction system pacing (CSP) is an alternative option for cardiac resynchronization therapy (CRT) in patients with heart failure remains an area of active investigation. OBJECTIVE: The purpose of this study was to assess the echocardiographic and clinical outcomes of CSP compared to biventricular pacing (BiVP). METHODS: This multicenter retrospective study included patients who fulfilled CRT indications and received CSP. Patients with CSP were matched using propensity score matching and compared in a 1:1 ratio to patients who received BiVP. Echocardiographic and clinical outcomes were assessed. Response to CRT was defined as an absolute increase of ≥5% in left ventricular ejection fraction (LVEF) at 6 months post-CRT. RESULTS: A total of 238 patients were included. Mean age was 69.8 ± 12.5 years, and 66 (27.7%) were female. Sixty-nine patients (29%) had His-bundle pacing, 50 (21%) had left bundle branch area pacing, and 119 (50%) had BiVP. Mean follow-up duration in the CSP and BiVP groups was 269 ± 202 days and 304 ± 262 days, respectively (P = .293). The proportion of CRT responders was greater in the CSP group than in the BiVP group (74% vs 60%, respectively; P = .042). On Kaplan-Meier analysis, there was no statistically significant difference in the time to first heart failure hospitalization (log-rank P = .78) and overall survival (log-rank P = .68) between the CSP and BiVP groups. CONCLUSION: In patients with heart failure and reduced ejection fraction, CSP resulted in greater improvement in LVEF compared to BiVP. Large-scale randomized trials are needed to validate these outcomes and further investigate the different options available for CSP.

Mapping and ablation of ventricular fibrillation substrate.

Ventricular fibrillation (VF) is a life-threatening arrhythmia and a common cause of sudden cardiac death (SCD). A basic understanding of its mechanistic underpinning is crucial for enhancing our knowledge to develop innovative mapping and ablation techniques for this lethal rhythm. Significant advances in our understanding of VF have been made especially in the basic science and pre-clinical experimental realms. However, these studies have not yet translated into a robust clinical approach to identify and successfully ablate both the structural and functional substrate of VF. In this review, we aim to (1) provide a conceptual framework of VF and an overview of the data supporting the spatiotemporal dynamics of VF, (2) review experimental approaches to mapping VF to elucidate drivers and substrate for maintenance with a focus on the His-Purkinje system, (3) discuss current approaches using catheter ablation to treat VF, and (4) highlight current unknowns and gaps in the field where future work is necessary to transform the clinical landscape.

Evaluation and Catheter Ablation of Ventricular Arrhythmias in Cardiac Sarcoidosis.

Ventricular arrhythmias are a common clinical manifestation in patients with cardiac sarcoidosis (CS) and other arrhythmogenic inflammatory cardiomyopathies (AIC). The management of sustained ventricular arrhythmias in these patients presents unique challenges. Current therapies include immunosuppressive, antiarrhythmic agents, and catheter ablation. Significant progress has been made in deciphering the importance of patient selection for ablation, systematic preablation evaluation, and optimal ablation timing, as well as ablation approaches and techniques. In this overview, we discuss the evaluation and management of ventricular arrhythmias in patients with CS, focusing on catheter ablation, which has evolved into an effective approach in reducing the burden of ventricular arrhythmias in these patients in the context of multifaceted treatment along with medical therapies.