The left circumflex coronary artery is susceptible to injury during mitral valve surgery because of its proximity to the mitral valve annulus. We report the case of a 73-year-old woman who had undergone mitral valve repair and experienced a perioperative myocardial infarction due to occlusion of the left circumflex coronary artery. After percutaneous coronary intervention, a fistulous communication had developed between the stented portion of the left circumflex coronary artery and the left atrium, which, to our knowledge, is the first report of such a complication. The patient underwent successful mitral valve replacement. Although injuries to the left circumflex coronary artery are rare during mitral valve surgery, we believe that increasing awareness of the risk will help to prevent potentially fatal complications. We also recommend that surgeons gather as much detail as possible about the patient's anatomy before operation, use careful and meticulous surgical techniques, and use transesophageal echocardiography to look for wall-motion abnormalities before closing the incision.
Keywords: Coronary artery fistula; coronary occlusion; heart valve prosthesis implantation/adverse effects; mitral valve annuloplasty; surgical complication.