Persistent left superior vena cava (PLSVC) with anomalous left hepatic vein drainage into the right atrium: role of imaging and clinical relevance.

Persistent left superior vena cava (PLSVC) is a very rare and yet the most commonly described thoracic venous anomaly in medical literature. It has a 10-fold higher incidence with congenital heart disease. PLSVC often becomes apparent when an unknown PLSVC is incidentally discovered during central venous line placement, intracardiac electrode/pacemaker placement or cardiopulmonary bypass, where it may cause technical difficulties and life-threatening complications. PLSVC is also associated with disturbances of cardiac impulse formation and conduction including varying degrees of heart blocks, supraventricular arrhythmias and Wolff Parkinson White syndrome. We describe the case of an 86-year-old male with a history of coronary artery disease and chronic atrial fibrillation who presented with worsening dyspnea and syncopal episodes. An ECG was consistent with complete heart block. During lead placement for the pacemaker, a left subclavian approach was unsuccessful. A left venogram was performed through the brachial vein that demonstrated a left superior vena cava. The diagnosis was confirmed with echocardiography using a bubble study and also a chest CT. The anatomy was unique as there was anomalous left hepatic vein drainage into the right atrium. The case provides insight into the diagnostic modalities and clinical considerations of this unusual thoracic venous anomaly.