[Atrial septal defect of sinus venous type diagnosed by transesophageal echocardiography intraoperatively].

We encountered a patient with atrial septal defect (ASD) of sinus venous type which had not been diagnosed preoperatively. A 70-year-old-man with angina pectoris was admitted to our hospital and coronary artery bypass grafting was scheduled. After induction of general anesthesia with fentanyl, propofol, midazolam, and vecuronium, operation was going smoothly. However, we found an abnormal rise of the value of Sv(O2). Transesophageal echocardiography (TEE) demonstrated ASD of sinous venous type which had not been diagnosed preoperatively. For this incidental diagnosis, operation was performed to repair ASD and was finished successfully. He was discharged from the hospital on postoperative day 18 without complications. We have demonstrated in this report that TEE is an important tool which should be used routinely to diagnose cardiac diseases which have not been diagnosed preoperatively.