Left-Sided Persistent Superior Vena Cava with Superior Hemiazygos Arch

Persistent Left-side Superior Vena Cava (PLSVC) is the congenital central venous anomaly draining into the right atrium in 82-90% of cases via coronary sinus produce no haemodynamically significant consequences. In few cases it may drain into the left atrium directly or through the pulmonary veins resulting in right to left shunt. During routine undergraduate dissection, we found a PLSVC formed by the union of left subclavian and left internal jugular veins behind the left sternoclavicular joint was terminated into the right atrium through a larger coronary sinus ostium. Before its termination, PLSVC received a left hemiazygos vein formed by the continuation of the superior and inferior hemiazygos veins. A larger but thin communicating vein was noted between the right superior vena cava and PLSVC. Prior knowledge about such variations is essential in all the intervention procedures on right atrium through the left subclavian approach and also like in our case, the larger coronary sinus ostium if found during transthoracic echocardiography should be considered as an indication for the diagnosis of PLSVC.