Surviving cardiac arrest from mitral annular disjunction: A case report

A 38-year-old man with no previous medical history presented to hospital after having an out-of-hospital cardiac arrest. He was found to have a ventricular fibrillation and was successfully resuscitated after receiving cardiopulmonary resuscitation and three shocks. Extensive investigations were performed which included an electrocardiogram that showed no significant abnormality, coronary angiogram which showed unobstructed arteries, and a flecainide challenge test which was negative for Brugada syndrome. A resting echocardiogram showed a myxomatous mitral valve with mild bi-leaflet bowing, trivial mitral regurgitation, normal left ventricular systolic function, and no other structural abnormalities. A cardiac magnetic resonance imaging showed no significant late gadolinium enhancement to suggest infarct or myocardial scarring. He was subsequently diagnosed with idiopathic ventricular fibrillation and treated with a subcutaneous internal cardioverter-defibrillator for secondary prevention. A follow-up echocardiogram was performed which revealed the presence of mitral annular disjunction which has been recently shown to be associated with significant life-threatening arrhythmias and sudden cardiac death. This case highlights the importance of improving awareness of mitral annular disjunction which is not often considered as a cause for adverse patient outcomes.