Anomalous origin of left coronary artery from pulmonary artery.

An anomalous origin of the left coronary artery from the pulmonary artery in a 26-year-old man was corrected by the ligation of the artery at its anomalous origin, followed by the construction of an aortocoronary bypass with a venous graft. The flow of blood to the myocardium was measured for the purpose of comparing the effect of the bypass method with that of the ligation method. The result suggested that the bypass method provided a greater flow of blood to the myocardium than did ligation alone.