Mitral Annular Disjunction Presenting With Ventricular Arrhythmia: A Case Report

Mitral annular disjunction (MAD) is an underrecognized structural abnormality increasingly linked to ventricular arrhythmias and sudden cardiac death. We report the case of a patient admitted for palpitations and chest discomfort, in whom a 12-lead surface electrocardiogram captured a short episode of ventricular tachycardia that terminated spontaneously, consistent with non-sustained ventricular tachycardia (VT). Coronary angiography demonstrated normal coronary arteries, prompting further evaluation with cardiac magnetic resonance imaging. CMR revealed a clear systolic separation between the posterior mitral annulus and the left ventricular myocardium, confirming the presence of MAD. It also identified focal papillary muscle fibrosis adjacent to the disjunction, an arrhythmogenic substrate strongly associated with malignant ventricular arrhythmias, with no evidence of ischemia or myocarditis. Left ventricular systolic function was preserved. The patient was started on medical therapy and referred for electrophysiological assessment due to the arrhythmic burden and high-risk structural findings. This case highlights the importance of considering MAD in patients presenting with ventricular arrhythmias despite normal coronary angiography. Multimodality imaging, particularly CMR, plays a pivotal role in identifying both structural and tissue abnormalities, refining risk stratification, and guiding management. Early recognition of MAD enables targeted follow-up, optimized therapy, and timely intervention to reduce the risk of life-threatening outcomes.