Bicameral Pacemaker Implant in an Extremely Rare Case of Left Superior Vena Cava Anatomic Variant

Abstract

The most common congenital venous anomaly of the thoracic systemic venous return is the persistence of the left superior vena cava (PLSVC), occurring in 0.3% to 0.5% of individuals in the general population, and in 12% of individuals with other congenital heart abnormalities. 50% of the patients with isolated PLSVC have other cardiac malformations (atrial septal defect, endocardial cushion or tetralogy of Fallot). The basis for persistence of the left superior vena cava (LSVC), usually associated with other cardiac malformations, is poorly understood. The presence of a PLSVC has a significant influence of the anatomy of the heart and venous system. There is very little in the literature that specifically addresses the potential importance of the incidental finding of PLSVC to surgeons, interventional radiologists, and other physicians actively involved in central venous access device placement. The current review is a case report of persistent left superior vena cava associated with severe disorders of intra-cardiac conduction leading to specific symptoms. This venous malformation was identifies incidentally in a 80 years old patient during the procedure of pacemaker implantation. The venography showed isolated PLSVC with a bridging vein that drained the right jugular and right subclavian vein and joined the left brachiocephalic vein to form the PLSVC, which descendent on the left side of the mediastinum and drained into the right atrium via a dilated coronary sinus.