RESUMEN
Unroofed coronary sinus syndrome is a rare congenital cardiac anomaly, involving some anatomical variations. Approximately 60% of patients with unroofed coronary sinus syndrome have a concomitant atrial septal defect, which is termed unroofed coronary sinus atrial septal defect (CSASD). The precise detection of these abnormalities has been usually difficult with conventional echocardiography, mostly due to its small and complex structures. Herein, we report a case with unroofed coronary sinus atrial septal defect, in which preoperative contrast-enhanced computed tomography (CT) was useful in the operative decision making. We successfully repaired the defective roof of the coronary sinus with a bovine patch, while eliminating the inter-atrial shunt. The patient's postoperative course was uneventful with no residual shunt.