[Thrombus in the Right Atrial Appendage Detected Incidentally during Coronary Artery Bypass Grafting;Report of a Case].

A 71-year-old male was admitted to our hospital for treatment of complete atrioventricular block. By cardiac catheterization, chronic occlusion was confirmed in the right coronary artery and circumflex branch, and coronary artery bypass grafting was planned. Although atrioventricular block disappeared by discontinuance of β-blocker, paroxysmal atrial flutter had been confirmed before surgery. After an incision into the pericardium, changes in the color of the right atrial appendage were observed, and a thrombus was detected at the site by epicardial echography. The right atrial appendage was removed together with the thrombus, and coronary artery bypass grafting was performed as scheduled. Pathological findings suggested myocardial tissues with ischemic changes and an organized thrombus exhibiting granulomatous changes. This case suggested the need to observe the right atrial appendage carefully during cardiac surgery in patients with risk factors for atrial thrombus.