Anomalous Left Coronary Artery Originating from the Pulmonary Artery

Case histories of two infants with anomalous origin of the left coronary artery from the pulmonary artery are presented.Both infants underwent ligation of the left coronary artery at its entrance into the pulmonary artery. One survived the operation and is asymptomatic 3 years postoperatively, whereas the second one died at surgery.A classification of instances of anomalous left coronary artery according to adequacy of the collateral circulation between the left and right coronary systems is proposed.Surgical ligation of the pulmonary artery orifice of the left coronary artery is indicated only if the presence of a left-to-right shunt into the pulmonary artery is demonstrated.If the direction of blood flow is from pulmonary artery to left coronary artery, surgical procedures should be aimed toward increasing either pulmonary artery oxygen content or left coronary artery perfusion pressure.