Abstract
A 48-year-old male patient underwent mitral annuloplasty for severe mitral regurgitation secondary to myxomatous degeneration of the mitral valve, with ruptured chordae. Intraoperative transesophageal echocardiography showed satisfactory repair. The patient developed postoperative atrial fibrillation and clinical and echocardiographic evidence of left ventricular outflow obstruction. Following conversion to sinus rhythm, the evidence for left ventricular outflow obstruction markedly improved. We suggest that postoperative atrial fibrillation may precipitate dynamic left ventricular outflow obstruction following mitral annuloplasty.