Anomalous origin of the left main coronary artery from the right coronary artery ostium-interarterial subtype: angiographic definition and surgical treatment.

Coronary artery anomalies occur infrequently compared to atherosclerotic disease; however, when they do occur, they can pose difficulty with coronary visualization and identification. Ectopic origin of the left mainstem coronary artery from the right sinus of Valsalva coursing between the great vessels is the rarest subtype of these anomalies, can be potentially serious, and presents unique problems for surgical treatment.