Anomalous origin of the left coronary artery from the right pulmonary artery.

A previously unknown coronary artery anomaly is reported: origin of the left coronary artery from the right pulmonary artery. This unusual anomaly can probably be explained by the theory of dual embryonic development of the coronary arteries from angioblastic buds in the truncus arteriosus. It is thought that these buds anastomose with a capillary network that is developing on the surface of the ventricles. Complete repair of this lesion with restoration of a two-coronary artery system was accomplished in a 10-month-old baby. The coronary artery was detached from the pulmonary artery, with a button of pulmonary artery being retained around the coronary artery ostium. Direct systemic arterial flow to the left coronary artery was established by anastomosis of the left coronary to the right subclavian artery.