[A case report of coronary sinus atrial septal defect].

We experienced an uncommon case of coronary sinus atrial septal defect, which was not associated with a left superior vena cava (LSVC). A 29-year-old woman, who experienced fatigue during moderate exercises, was found to have the atrial septal defect located in the lower part of the septum by echocardiography preoperatively. On operation, the coronary sinus ASD was diagnosed. The ostium of coronary sinus was located in the left atrium. This type is classified as partially unroofed coronary sinus without LSVC. Our case, in the absence of the LSVC, was repaired by simple closure of the coronary sinus ASD, so the coronary veins drained into the left atrium. Postoperative course was uneventful.