Current understanding of mitral valve prolapse syndrome and related arrhythmia: State-of-the-Art review.

Mitral valve prolapse (MVP) is the most common cause of primary (degenerative) mitral regurgitation and represents a heterogeneous disease spectrum with generally benign prognosis but potentially serious complications. Advances in imaging have refined diagnostic criteria, reducing historical overdiagnosis and clarifying the morphologic continuum from fibroelastic deficiency to extensive myxomatous degeneration (Barlow's disease). Beyond mitral regurgitation and infective endocarditis, a small but clinically important subset of patients is at increased risk of malignant ventricular arrhythmias and sudden cardiac death, giving rise to the concept of arrhythmogenic MVP. This phenotype is characterized by a combination of clinical, anatomical, myocardial, and electrical features rather than a single abnormality. Key associated findings include bileaflet prolapse, female sex, electrocardiographic repolarization changes, frequent or complex ventricular ectopy, myocardial fibrosis detectable by cardiac magnetic resonance, abnormal tissue Doppler signals, and mitral annular disjunction (MAD). MAD, including both true MAD and the more common pseudo-MAD, contributes to excessive mobility of the mitral valve apparatus, abnormal systolic annular motion ("curling"), and repetitive mechanical stress on the papillary muscles and inferobasal left ventricular myocardium, promoting fibrosis and arrhythmogenesis. Importantly, arrhythmic risk may persist even after surgical correction of mitral regurgitation, likely due to established myocardial substrate. Contemporary registry data confirm the heterogeneity of MVP and suggest that true primary arrhythmogenic MVP is relatively uncommon but identifiable using detailed echocardiographic and electrocardiographic assessment. Overall, arrhythmogenic MVP should be viewed as a syndrome spanning a spectrum from benign to malignant, underscoring the need for integrated risk stratification and targeted follow-up. This review summarizes the recent progress in understanding of this complex entity summarizing recent expert recommendations and novel registry data.