Persistent Left Superior Vena Cava Draining the Pulmonary Veins

Persistence of the left superior vena cava is not uncommon in children with congenital heart disease and is occasionally found in adults at thoracotomy. The anomalous vena cava usually carries venous blood from the upper part of the body to the right atrium via the coronary sinus and has little functional significance. In the four patients we describe, however, the left superior vena cava drained arterial blood from some or all of the pulmonary veins into the left innominate vein, and thence into the right atrium. In three of them it was the sole channel by which oxygenated blood could reach the systemic circulation.