Free-floating left atrial ball thrombus following mitral valve replacement.

We report the case of a 51-year-old woman who underwent mitral valve replacement for prolapse with severe regurgitation, depressed ejection fraction, and atrial fibrillation. Two weeks post-operatively, a transesophageal echocardiogram was performed for bacteremia. The patient was found incidentally to have a large free-floating ball thrombus in the left atrium. The patient was managed with anticoagulation because of the high-risk nature of repeat surgery. One month following diagnosis, the patient still had persistent thrombus in the left atrium seen on transthoracic echocardiography despite therapeutic anticoagulation. Free-floating ball thrombus is a rare and dramatic finding seen on echocardiography in patients with mitral valve disease.