Abstract
BACKGROUND: On-pump beating coronary artery bypass grafting (CABG) is a procedure that uses cardiopulmonary bypass to maintain circulation and it is a useful technique for CABG in patients with severely impaired cardiac function. Here, we report a case of left atrial rupture that occurred during CABG. Reports of left atrial injury are rare, and there have been no previous reports of such cases associated with on-pump beating CABG. CASE PRESENTATION: An 80-year-old man with a history of myocardial infarction was admitted to another hospital for acute heart failure. Coronary angiography revealed triple-vessel disease, and echocardiography showed reduced left ventricular function and moderate mitral regurgitation. He was transferred to our hospital for coronary artery bypass grafting and the operation was scheduled. Surgery was started with the intention of off-pump CABG, but due to circulatory instability, the patient was converted to on-pump beating CABG. While the heart was being dislocated and anastomosis was being performed, sudden bleeding from the left atrium occurred. To achieve hemostasis, we needed to arrest the patient's heart. A 5-cm laceration along the posterior mitral annulus was found in the left atrium and repaired with a bovine pericardial patch. Mitral annuloplasty with a flexible ring was performed simultaneously. He recovered uneventfully. CONCLUSIONS: The left atrial rupture during on-pump beating coronary artery bypass grafting is extremely rare. The wall of the atrium is thought to have been damaged by the stress applied during the displacement of the heart and the impact of the enlarged mitral regurgitant jet. Repair under cardiac arrest is necessary, and in some cases, mitral annuloplasty may be additionally required.