Arrhythmogenic Mitral Valve Prolapse: Looking Beyond Mitral Regurgitation.

JACC. Case reports · 2026-08-21 · Case report

Abstract

BACKGROUND: Mitral valve prolapse (MVP) is usually evaluated through the severity of mitral regurgitation (MR), yet some patients may exhibit an arrhythmogenic phenotype associated with life-threatening ventricular arrhythmias. CASE SUMMARY: A 70-year-old asymptomatic woman with Barlow disease was referred for MR reassessment. Echocardiography showed bileaflet prolapse, moderate to severe MR, mitral annular disjunction, and left-sided chamber remodeling. Ambulatory electrocardiographic monitoring revealed frequent polymorphic premature ventricular complexes. Before work-up completion, she experienced an out-of-hospital ventricular fibrillation with cardiac arrest. Cardiac magnetic resonance demonstrated inferolateral myocardial fibrosis. She underwent implantable cardioverter-defibrillator placement, followed by mitral valve repair and surgical ablation. DISCUSSION: This case highlights the need to identify arrhythmogenic MVP early, using an integrated clinical, electrocardiographic, echocardiographic, and cardiac magnetic resonance approaches for individualized risk stratification. TAKE-HOME MESSAGE: In patients with MVP, arrhythmic risk stratification should go beyond MR severity, integrating red flags with clinical assessment, serial multimodality imaging, and a multidisciplinary team involving imaging, electrophysiology, and surgical expertise.