Reversed Remodeling Unveils Mitral Annular Disjunction.

BACKGROUND

Mitral annular disjunction (MAD) is a structural abnormality increasingly recognized in association with mitral valve prolapse (MVP) and cardiomyopathy. Its clinical significance in nonischemic cardiomyopathy (NICM) is less understood.

CASE SUMMARY: A 60-year-old man with NICM presented with progressive dyspnea and atrial fibrillation. Initial cardiac magnetic resonance imaging (CMR) showed severe left ventricular (LV) dilation, reduced ejection fraction (16%), and mild MVP without MAD. After 18 months of guideline-directed medical therapy, LV function normalized, but severe mitral regurgitation and significant MAD became more apparent. Surgical repair with a quadrangular resection and annuloplasty was successful, resolving symptoms.

DISCUSSION: This case highlights the role of CMR in identifying MAD in NICM, and demonstrates how reverse LV remodeling can unmask MAD and MVP. Reduced tethering forces on mitral chordae after LV size reduction likely contributed to revealing the underlying pathology of bi-leaflet redundancy and prolapse.