Unexpected sudden cardiac arrest due to ventricular fibrillation in a 7-year-old boy with Duchenne muscular dystrophy.

A previously asymptomatic 7-year-old boy with Duchenne muscular dystrophy unexpectedly developed sudden cardiac arrest with no preceding illness. An automated external defibrillator confirmed the presence of ventricular fibrillation. Cardiac MRI showed prominent myocardial fibrosis with no evidence of acute inflammation. Whole exome sequence revealed no associated pathological variance for lethal ventricular arrhythmias. Life-threatening ventricular fibrillation can occur in young patients with Duchenne muscular dystrophy.