Persistent left superior vena cava and right superior vena cava drainage into the left atrium without arterial hypoxemia

A 46 year old patient who presented with an acute myocardial infarction was discovered to have a systemic venous communication with the left heart during attempted insertion of a pulmonary flotation catheter. There was no evidence of cyanosis or systemic arterial desaturation. A right superior vena cava that emptied into the right superior pulmonary vein and a persistent left superior vena cava draining into the coronary sinus were confirmed pathologically after death related to a brain abscess. The embryology, physiology and noninvasive diagnostic approach to this unique venous anomaly are discussed.