Mitral Annular Disjunction: Review of an Increasingly Recognized Mitral Valve Entity

Area of Science:

• Cardiology
• Cardiac Imaging
• Electrophysiology

Background:

• Mitral annular disjunction (MAD) is the atrial displacement of the mitral valve annulus hinge point from the ventricular myocardium.
• MAD can cause paradoxical annular expansion during systole and is linked to mitral valve prolapse (MVP), leaflet degeneration, and myocardial fibrosis.
• Patients with MAD and MVP may have similar presentations, with MAD potentially explaining adverse outcomes in some MVP patients.

Purpose of the Study:

• To review the history, pathophysiology, controversy, prevalence, clinical implications, and imaging considerations of Mitral Annular Disjunction (MAD).
• To emphasize the role of Cardiac MRI in diagnosing and quantifying MAD, MVP, and associated fibrosis.
• To highlight the association between MAD distance and the risk of malignant cardiac arrhythmias.

Main Methods:

• Review of existing literature on Mitral Annular Disjunction (MAD).
• Focus on diagnostic capabilities of Cardiac MRI for MAD, MVP, and myocardial/papillary muscle fibrosis.
• Analysis of clinical outcomes related to MAD distance and associated cardiac conditions.

Main Results:

• A MAD distance of 5 mm or longer is associated with an increased risk of malignant cardiac arrhythmia.
• Cardiac MRI effectively identifies and quantifies MAD, MVP, and fibrosis, which are crucial for risk stratification.
• MAD is an important consideration in cardiac imaging, particularly for patients with MVP and unexplained arrhythmias.

Conclusions:

• MAD is a significant finding in cardiac imaging, especially in patients with MVP and arrhythmias.
• Cardiac MRI is a valuable tool for diagnosing MAD and associated pathologies, aiding in risk assessment and treatment planning.
• Identifying and quantifying MAD can help predict and potentially improve outcomes after electrophysiology procedures and mitral valve surgery.