Mitral Annular Disjunction: Pathophysiology, Pro-Arrhythmic Profile and Repair Pearls

Mitral annular disjunction (MAD) is a structural abnormality defined by a distinct separation of the mitral valve annulus-left atrial wall continuum and the basal aspect of the posterolateral left ventricle. This anomaly is often observed in patients with myxomatous mitral valve prolapse. Importantly, MAD has been strongly associated with serious ventricular arrhythmias and predisposes to sudden cardiac death. Therefore, we have to emphasize the need to diagnose this morphologic and functional abnormality in routine practice in order to facilitate optimal mitral valve repair and minimize patient risks. Nevertheless, clinical knowledge regarding MAD still remains limited. In the present review, we aim to shed light on several aspects of MAD, including distinct anatomical and pathophysiological characteristics, imaging modalities, association with ventricular arrhythmias, and current methods of treatment.