Autonomic modulation in ventricular arrhythmias: Clinical insights and therapeutic opportunities

Recent evidence establishes robust causal relationships between autonomic nervous system dysfunction and ventricular arrhythmias through multiple converging mechanisms. Direct neural recording studies demonstrate that sympathetic discharge from the left stellate ganglion immediately precedes ventricular fibrillation. At the same time, mechanistic investigations reveal that nerve growth factor-mediated sympathetic sprouting creates heterogeneous innervation patterns, directly triggering arrhythmogenesis. Although genetic syndromes like Brugada syndrome show opposing patterns with parasympathetic dominance driving arrhythmic events, disease-specific autonomic patterns have emerged, with heart failure and post-myocardial infarction displaying sympathetic overactivation and parasympathetic withdrawal. Current predictive tools show significant advances, but implementation challenges persist. The most clinically validated method is meta-iodobenzylguanidine imaging, and when using standardized protocols, heart rate variability analysis shows dependable prognostic value. Therapeutic interventions reveal mixed clinical outcomes. While beta-blockers remain effective in reduced ejection fraction populations, questions regarding benefits in preserved ejection fraction patients persist. Stellate ganglion blocks show promise for managing electrical storms, achieving a 62% reduction in ventricular arrhythmias. However, major clinical trials have yielded disappointing results for spinal cord stimulation and cardiac sympathetic denervation. Future directions emphasize personalized medicine approaches integrating genetic data, advanced imaging, and artificial intelligence for biomarker-guided therapy selection, representing the next frontier in precision cardiology for arrhythmia management.