Free-Floating Thrombus in the Left Atrium

A 72-year-old, asymptomatic patient with a history of permanent atrial fibrillation was admitted to our hospital for an echocardiographic follow-up 6 months after a mitral valve replacement. Two-dimensional transthoracic and transesophageal echocardiography revealed a freely moving mass in the left atrium. Three-dimensional transesophageal echocardiography (3D-TEE) demonstrated a ball-like thrombus (yellow arrows) bouncing around the atrium like a ball in a pinball machine. The mass was striking repeatedly against the mitral valve without obstructing it, due to its large size (A and B, Online Videos 1 and 2). 3D-TEE is a novel echocardiographic technique that helps to evaluate and differentiate a cardiac mass, providing additional information about its shape, size, mobility, attachment point, and spatial orientation (1,2). Blue arrow = spontaneous contrast into the left atrium. Ao = aorta; LA = left atrium; LAA = left atrial appendage; LV = left ventricle; Mv = prosthetic mitral valve.

• Received August 23, 2010.
• Accepted September 6, 2010.

• American College of Cardiology Foundation