Malignant Mitral Valve Prolapse With Life-Threatening Ventricular Arrhythmias

CLINICAL CONDITION: A 45-year-old woman with long-standing bileaflet myxomatous mitral valve prolapse (MVP), mitral annular disjunction, and mild mitral regurgitation (MR) developed near-syncope and was found to have frequent polymorphic ventricular tachycardia on ambulatory monitoring. Despite medical therapy, she experienced recurrent ventricular fibrillation and multiple implantable cardioverter-defibrillator (ICD) shocks. KEY QUESTIONS: Can malignant arrhythmogenic MVP occur in the absence of severe MR or detectable myocardial fibrosis on cardiac magnetic resonance imaging? Which combination of electrical and mechanical risk markers identifies patients at imminent risk for sudden cardiac death? Can early surgical correction of the mechanical substrate durably suppress ventricular arrhythmias? OUTCOME: The patient underwent mitral valve repair. Since then, she has remained free of arrhythmias and ICD shocks. TAKE-HOME MESSAGES: Malignant MVP can manifest with multifocal ventricular tachycardia independent of MR severity. Prophylactic ICD placement followed by definitive mitral valve repair reduces arrhythmic triggers and prevents sudden cardiac death.