Mitral valve prolapse (MVP) is associated with malignant ventricular arrhythmias (VA) and sudden cardiac death. A proper electrophysiological and echocardiographic characterization of this population is missing. Moreover, the effects of mitral valve repair on the arrhythmic burden are still matter of debate. The investigators sought to explore the role of the arrhythmic substrate in the risk stratification of patients with MVP and to assess whether mitral surgery is followed by a significant modification of the baseline arrhythmic pattern.