Mitral Annular Disjunction: Epidemiology, Diagnostic Methods, Prognosis, and Novel Implications.

Abstract

Mitral annular disjunction (MAD) is an increasingly recognized structural abnormality of the mitral valve apparatus, often associated with mitral valve prolapse and a heightened risk of ventricular arrhythmias and sudden cardiac death. It is defined by a separation between the mitral annulus and the left ventricular myocardium, best visualized during systole. In this review, we present an updated and comprehensive overview of MAD, drawing from recent large-scale imaging studies, expert consensus documents, and newly proposed classifications such as true versus pseudo-MAD. We discuss its prevalence, anatomical features, and diagnostic challenges across multiple imaging modalities, including transthoracic and transesophageal echocardiography, cardiovascular magnetic resonance, and computed tomography. We also explore its pathophysiological role in arrhythmogenesis, its prognostic implications, and current management strategies. Special attention is given to risk stratification based on imaging and cardiac rhythm findings, and we propose a practical clinical framework to guide decision-making. This review aims to support clinicians in recognizing MAD as a potentially arrhythmogenic condition that requires systematic evaluation and follow-up.