Abstract
BACKGROUND: Coronary artery aneurysm (CAA) is defined as dilatation exceeding 1.5 times the width of the normal adjacent coronary artery segments. CAA usually causes few symptoms, and rupture is rare, but can be lethal due to cardiac tamponade when it does occur. CASE PRESENTATION: A 79-year-old woman presented with presyncope and back pain. Emergency surgery was performed based on a diagnosis of cardiac tamponade due to either rupture of coronary arteriovenous fistula or CAA. At surgery, a rupture site was located on the wall of the giant CAA, with a diameter of 55 mm, originating from the ostium of the right coronary artery. Suture closure of the inflow and outflow of the aneurysm was performed, and the aneurysmal cavity was obliterated by multiple sutures. The patient made an uneventful recovery and was discharged from hospital on postoperative day 13. CONCLUSION: On the basis of this case, we propose considering rupture of a CAA as one of the causes of cardiac tamponade.