Anomalous origin of the left main coronary artery from the right anterior aortic sinus.

Anomalous origin of the left main coronary artery from the right sinus of Valsalva is an uncommon problem, occurring in four distinct patterns. When the left main coronary artery passes between the aorta and the pulmonary trunk, acute myocardial ischemia or sudden death may occur. Angiography is required in establishing a diagnosis. Surgical correction or bypass surgery are sometimes indicated. The authors report two cases of anomalous origin of the left main coronary artery and discuss the anatomic variants, clinical significance, and technical considerations in both diagnosis and management.