Formation of a Free Floating Left Atrial Thrombus Despite Three Weeks of Anticoagulation
A 46-year-old woman with exertional dyspnea consequent to severe rheumatic mitral valvular stenosis had a small thrombus in the left atrial appendage documented by transesophageal echocardiography. Warfarin and aspirin therapy was instituted, and she was referred for elective surgical repair. Three weeks later she was admitted for acute pulmonary edema. An immediate echocardiogram revealed a 2.8×2.9-cm free-floating, spheric-shaped thrombus within the left atrial cavity. The thrombus was free from the atrial wall, moving within the cavity. It had a recurring, rhythmic motion in the left atrium while intermittently obstructing the mitral orifice (Figures 1 and 2⇓). The small thrombus that had been observed at the first admission was also seen.
The thrombi in the left atrial cavity and appendage were removed and the mitral valve replaced with a St Jude medical mechanical prothesis (St Jude Medical, Inc). Her postoperative period was uneventful.
The extracted free-floating thrombus measured 2.8×2.9×2.9 cm. It was a spherical mass with a fissure on its surface. It had no attachment to the left atrial wall or septum. This suggested that the thrombus had had an attachment to the atrial wall initially and then became a free-floating thrombus after its detachment from the atrial lining.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
Circulation encourages readers to submit cardiovascular images to the Circulation Editorial Office, St Luke’s Episcopal Hospital/Texas Heart Institute, 6720 Bertner Ave, MC1-267, Houston, TX 77030.