A 40 year old Japanese man fainted suddenly while fishing and was brought to hospital. He fainted again in the outpatient department. Electrocardiography showed ventricular fibrillation (fig 1A), and sinus rhythm was recovered by defibrillation with 200 J. He had no history of syncope or life threatening arrhythmias. A grade V/VI continuous murmur was accompanied by a diastolic thrill along the left sternal border. Electrocardiography showed negative T waves in leads II, III, aVF, and V4–6. Transoesophageal echocardiography with colour Doppler imaging showed an aneurysm of the right coronary sinus of Valsalva, which displaced towards the right ventricle, and had systolic–diastolic turbulent flow from the aorta into the right ventricle (fig 2).