[Mitral Valve Replacement under Ventricular Fibrillation through Right Thoracotomy for Severe Mitral Regurgitation with Low Left Ventricular Function after Coronary Artery Bypass Grafting；Report of a Case].

A 64-year-old woman had undergone coronary artery bypass grafting (CABG:left internal thoracic artery-left anterior descending artery, right internal thoracic artery-1st diagonal branch, saphenous vein graft-posterior descending artery) 5 years before. However, she was referred to us due to worsening of dyspnea. Severe mitral regurgitation with tethering and tricuspid regurgitation were observed by echocardiography, and low left ventricular function with ejection fraction of 32.6% was noted. Coronary artery computed tomography revealed patency of all grafts, and the right internal thoracic artery ran across the front of the ascending aorta. To avoid injuring the patent grafts, mitral valve replacement under ventricular fibrillation and tricuspid annuloplasty were performed with a right thoracotomy approach. The postoperative course was uneventful, and she was discharged in an improved state on hospital day 28. This method appears safe and useful for avoiding secondary injuries in patients with severe mitral regurgitation with low left ventricular function after CABG.