Sudden cardiac death (SCD), the most devastating complication of hypertrophic cardiomyopathy (HCM), is primarily triggered by ventricular tachycardia or fibrillation. Despite advances in knowledge, the mechanisms driving ventricular arrhythmia in HCM remain incompletely understood, stemming from an interplay of multiple pro-arrhythmic factors. Myocyte disarray and myocardial fibrosis form a structural substrate favorable to re-entrant arrhythmias by altering myocardial electrophysiological properties, while cellular abnormalities predominate in patients without evident structural remodeling. Traditional SCD risk prediction models rely on clinical risk factors and regression-based risk estimation, often overlooking specific arrhythmic substrates. Emerging techniques now allow for the direct assessment of these substrates, providing deeper insights into the arrhythmogenic mechanisms and paving the way for more personalized SCD risk stratification. This review explores the contribution of cellular, structural, and electrophysiological substrates to arrhythmic risk in HCM, emphasizing their distinct roles. Furthermore, it highlights the potential of substrate-based approaches to refining SCD prevention strategies and improving outcomes for patients with HCM.

Atrial fibrillation is the most frequent arrhythmia in the general population and is not only associated with significant morbidity and mortality but it also ad

Background: Cardioneuroablation (CNA) is a recently introduced catheter-based therapy for vasovagal syncope (VVS), involving the modulation of the cardiac autonomic nervous system. Over the past decade, the body of evidence supporting CNA has consistently grown, sparking increased interest, and leading to broader adoption of this novel therapy for VVS treatment. However, several knowledge gaps persist, particularly concerning clinical indications, methodology, and long-term outcomes. Purpose: The aim of this survey is to provide a comprehensive overview of the daily utilization of CNA in Europe. Methods and Results: Among 204 participants, half reported that they are already performing CNA in their centres. The survey indicated CNA as an emerging therapy, with most centres initiating this treatment within the last two years. A significant majority of those who responded (71%) adopted a systematic approach by targeting ganglionated plexuses (GPs) in both the right atrium (RA) and left atrium (LA) as their first-line approach. The second most common approach (16%) involved performing ablation LA GPs only in the cases where there is no response following RA ablation. Figure 1 shows the GPs usually targeted for ablation. The most frequent procedural endpoint was the increase in the heart rate. Ninety percent of respondents relied on an anatomical approach for GP localization, while 59% also guided the procedure using electrogram analysis. Less frequently used approaches included pre-procedural imaging (20%), high-frequency stimulation (17%), and spectral analysis (10%). Only 11% of physicians discharged patients who underwent CNA without anticoagulation or antiplatelet therapy. In most cases (58%), respondents discharged their patients with anticoagulation, while 28% on single antiplatelet therapy. Overall, CNA is considered an effective procedure (80% of responders rating its effectiveness at or above 70%) and a safe procedure (with an estimated 1% rate of procedure-related complications, with symptomatic sinus tachycardia being the most frequently reported). Conclusions: This survey confirmed high expectations for the future of this therapy, as most responders anticipate that CNA will be indicated as a first-line therapy for patients with recurrent cardioinhibitory VVS. Future efforts are necessary to standardize the procedural flow and peri-procedural patient management.

Background: Arrhythmia-induced Cardiomyopathy (AiCM) represents a subtype of heart failure (HF) in the context of a sustained arrhythmia. However, clear definitions and management recommendations for AiCM are lacking. Purpose: The European Heart Rhythm Association Scientific Initiatives Committee (EHRA SIC) conducted a survey to determine the current definitions and management of patients with AiCM among European and non-European electrophysiologists. Methods: A 25-item online questionnaire was developed and distributed among EP research network centres between September 4th and October 5th 2022. Results: Out of the 206 respondents, 16% were females and the most (33%) were between 40-49 years old. Most of the respondents were EP-Specialists (81%) working at a University Hospital (47%). While most participants (67%) agreed that AiCM should be defined as a left ventricular ejection fraction (LVEF) impairment after new onset of an arrhythmia and/or LVEF recovery after treatment of the culprit arrhythmia, only 35% identified a specific LVEF drop/improvement to diagnose AiCM, the majority (50%) agreeing with a 10% change in LVEF (Figure) but with the rest of the experts choosing a wide range of values (from 5 to 20% LVEF drop). Most respondents used all available therapies in AiCM patients: catheter ablation was chosen by 93%, electrical cardioversion by 83%, antiarrhythmic drugs by 76% and adjuvant HF treatment were used by 76%. 83% of respondents indicated that adjuvant HF treatment should be started at first diagnosis of HF prior to antiarrhythmic treatment and 84% agreed that the therapy should be stopped within six months after LVEF normalization. Responses for the optimal time point for the first reassessment of LVEF during FU varied markedly (1 day to over 6 months after antiarrhythmic treatment). Conclusion: This EHRA Survey reveals varying practices in defining and managing AiCM among European and non-European physicians. There is an unmet need for a consensus in the definition and management of AiCM patients to improve patient care.Figure