A free floating ball thrombus in the left atrial cavity

Abstract

A 65-year-old woman with a medical history of mitral valve stenosis was admitted to our hospital with paroxysmal dyspnea, orthopnea, and presyncopal attacks, which started 24 hours before admission. The patient was in atrial fibrillation and had been treated with digitalis, diuretic, β-blockers, and dicumarole (the last international normalized ratio, 3 days earlier, had been 2.5). Results of physical examination, chest radiography, and electrocardiography were consistent with the underlying mitral valve stenosis. Routine transthoracic echocardiography revealed a stenotic mitral valve and a large left atrium with an occasional appearance of a floating mass within the atrium but not well visible. Transesophageal evaluation soon after revealed a large, round ball-like thrombus with well-demarcated borders, which was free floating in the left atrial cavity, occluding the stenotic mitral valve transiently but completely. The stenotic mitral valve seemed to protect the patient from systemic embolization by the thrombus. The variation in position was not coincident with the cardiac cycle, and the motion of the thrombus was unpredictable (Fig 1). The patient subsequently underwent urgent cardiac operation with removal of the circular mass from the left atrium and mitral valve replacement. Indeed, no attachment of the mass was found at operation, and the histologic examination proved that it was a thrombus. She was discharged on postoperative day 7 in stable condition. Discussion. Left atrial ball thrombus appears to be an unusual occurrence. Wood, who first applied the term ball thrombus to this entity in 1814, described autopsy findings in From the Department of Cardiology, University of Athens, Hippokration Hospital, Athens, Greece. Received for publication July 12, 1999; accepted for publication Aug 11, 1999. Address for reprints: Costas Tsioufis, MD, 4, Athanasiou Diakou St, 15127 Melissia, Greece. J Thorac Cardiovasc Surg 1999;118:1120-2