2024/8 - Mitral annular disjunction: where is the boundary between normality and disease? [Journal Club]-Mitral annular disjunction: where is the boundary between normality and disease?

Mitral annular disjunction: where is the boundary between normality and disease?

Video Transcription

Video Summary

The JCMR Journal Club session focused on mitral annular disjunction (MAD) and its relationship to mitral valve prolapse and arrhythmic risk. The speaker presented a consecutive CMR study of 441 patients, showing that MAD was common but highly dependent on how it was measured. A key finding was that small, limited MAD—especially under 4 mm—appeared benign and was not associated with ventricular arrhythmias or adverse outcomes. In contrast, more extensive MAD, particularly greater than 6 mm and often seen with bileaflet mitral valve prolapse, was linked to ventricular ectopy, myocardial fibrosis, and higher arrhythmic risk.<br /><br />The discussion emphasized that MAD should not be viewed as a simple yes/no diagnosis. Instead, its clinical importance depends on extent, imaging context, and additional risk features such as fibrosis, curling, ECG abnormalities, and arrhythmia burden. The panel also discussed differences between echocardiography, CMR, and CT, noting that CMR remains the preferred modality because it evaluates both anatomy and fibrosis. The session concluded that MAD exists on a spectrum, with a “good” limited form and a potentially “bad” extended form requiring closer clinical integration.

Keywords

mitral annular disjunction

mitral valve prolapse

arrhythmic risk

cardiac magnetic resonance

ventricular arrhythmias

myocardial fibrosis

bileaflet prolapse

echocardiography

ventricular ectopy