Dual nature of mitral annular disjunction: normal variation or pathological precursor?

Area of Science:

• Cardiology
• Cardiac Anatomy
• Electrophysiology

Background:

• Mitral annular disjunction (MAD) is a spatial displacement of the mitral valve leaflet hinge points.
• Historically viewed as an anatomical curiosity, MAD is increasingly recognized for its clinical significance.
• MAD is associated with mitral valve prolapse and cardiac arrhythmias.

Purpose of the Study:

• To review the spectrum of mitral annular disjunction presentations.
• To discuss diagnostic challenges associated with MAD.
• To elucidate the potential impact of MAD on patient outcomes.

Main Methods:

• Literature review of existing studies on mitral annular disjunction.
• Analysis of clinical observations and case reports.
• Synthesis of data regarding prevalence, types, and clinical associations of MAD.

Main Results:

• Two types of MAD exist: atrial (a-MAD) and ventricular (v-MAD).
• Prevalence of a-MAD varies widely (7.2-96.0%), while v-MAD prevalence is around 25%.
• a-MAD is linked to mitral valve prolapse, ventricular arrhythmias, and sudden cardiac death.

Conclusions:

• MAD, particularly a-MAD, is a clinically relevant finding impacting risk stratification.
• Further research is needed to understand the role of v-MAD in cardiac pathology.
• Accurate diagnosis and understanding of MAD are crucial for patient management.