Catastrophic myocardial ischemia resulting from a left coronary artery anomaly with an origin in the right sinus of Valsalva

A congenital left coronary artery anomaly originating from the right aortic sinus is a rare congenital defect associated with the risk of sudden death in young individuals. In most cases, the proximal portion of the anomalous left coronary artery exists between the ascending aorta and pulmonary trunk, and it has an intramural aortic course; this could critically impair the left coronary flow owing to compression of the anomalous left main trunk between the great vessels during exercise. Herein, we report a 14-year-old boy who experienced cardiac collapse due to an acute myocardial infarction after long-distance running. After resuscitation using percutaneous cardiopulmonary support, computed tomography and coronary angiography revealed an anomalous origin of the left main coronary artery in the right sinus of Valsalva and a proximal course between the aorta and pulmonary trunk. The patient was successfully treated using an unroofing procedure of the intramural left coronary artery.