We herein report a 64 year-old male who had an incidental finding of a persistent left superior vena cava (SVC) revealed by intraoperative transesophageal echocardiography (TEE) during a Maze procedure with left atrial appendage ligation. During the intraoperative TEE, an incidental dilated coronary sinus \u3e 1.1 cm was noted which prompted further evaluation and aided in our ultimate diagnosis. Consequently, significant additional surgical dissection and manipulation were required to isolate the left upper pulmonary vein. This case report reviews the anatomy and embryology of a persistent left SVC, discusses its clinical implications, and identifies surgical considerations for treatment
