Mitral annular disjunction (MAD) is an abnormal atrial displacement of the mitral valve leaflet hinge point. MAD is gaining clinical importance for several studies reporting its association to mitral valve prolapse (MVP), complex ventricular arrhythmias and sudden cardiac death. On the other hand, other studies found MAD as an extremely diffuse anatomical variant of mitral valve annulus without any pathological implication. Cardiac Magnetic Resonance is the non-invasive gold standard for myocardial characterization, with the possibility of accurate anatomical and functional evaluation associated to the evaluation of focal and interstitial fibrosis, resulting useful in the identification of arrhythmic substrate and for patients risk stratification. Additionally, Cardiac Magnetic Resonance (CMR) was found to be superior to echocardiography not only in term of tissue characterization, but also in the identification of small MAD. Therefore, in relation to the scarcity of data about MAD prevalence and pathological potential, we set a large multicenter retrospective study aimed to evaluate prevalence of MAD in patients submitted to CMR independently by the clinical suspicion, and to evaluate the association with prolapse and arrhythmias.