Malignant Mitral Valve Prolapse

Mitral valve prolapse (MVP) is the most frequent cause of primary mitral regurgitation in western countries. The diagnosis can be suspected from cardiac auscultation in some cases but is mostly confirmed by echocardiography. MVP has been for long suspected of being more than a benign disease. Nonspecific symptoms and major consequences, such as symptomatic severe mitral regurgitation, infective endocarditis, and cerebrovascular accidents, have been reported as nonarrhythmic complications of MVP. In some patients, atrial or ventricular arrhythmias can occur as serious clinical manifestations even in the absence of significant mitral regurgitation or hemodynamic compromise. Though still controversial, arrhythmic MVP patients are likely at increased risk of sudden cardiac death as compared with either nonarrhythmic MVP patients or the general population. Prior cardiac arrest and sustained ventricular tachycardia are strong predictors of sudden cardiac death in patients with MVP. Other features, such as electrocardiographic abnormalities (QT interval prolongation, repolarization abnormalities), flail mitral leaflet, significant mitral regurgitation, left ventricular (LV) dysfunction, or the presence of ventricular fibrosis, have also been highlighted as potential predictors of sudden cardiac death. Although the propensity of MVP to cause sudden cardiac death has been extensively discussed because of the high prevalence of MVP in the general population, no specific recommendations for risk stratification of patients with MVP have been defined in the current European and American guidelines. Refining risk factors and identifying mechanisms causing/ associated with malignant arrhythmias are of paramount clinical significance.