This special electrophysiology-themed issue of JACC, summarized by Dr. Valentin Fuster, dives into cutting-edge research on atrial fibrillation, pulsed field ablation, sudden cardiac arrest in athletes, and preventive strategies in congenital heart disease. From new therapies like finerenone to breakthrough mapping techniques, this episode captures the evolving sophistication and promise of arrhythmia management in modern cardiology.