Persistent Left Superior Vena Cava Draining into the Coronary Sinus: A Case Report

Persistent left superior vena cava (PLSVC) is a congenital anomaly of the thoracic venous system resulting from the abnormal persistence of an embryological vessel that normally regresses during early fetal life. This anomaly is often discovered incidentally during surgery, cardiovascular imaging or invasive cardiovascular procedures. In most cases, a PLSVC drains into the right atrium through the coronary sinus. In the remainder of cases, it enters directly or through the pulmonary veins into the left atrium. A dilated coronary sinus on echocardiography should always raise the suspicion of a PLSVC as it has important clinical implications. The diagnosis should be confirmed by saline contrast echocardiography. We report a patient with persistent left superior vena cava with an enlarged coronary sinus and normal right superior vena cava.