Echocardiographic features of right atrial thrombi.

The clinical and echocardiographic features of six patients in whom a right atrial thrombus was detected using two-dimensional echocardiography are reported. In four patients with acute cor pulmonale, the thrombus appeared as a coiled mass moving freely within the right atrium and prolapsing through the tricuspid valve. In another patient referred for syncope, a large coiled mass attached to the lateral wall of the right atrium was seen prolapsing regularly through the tricuspid valve, simulating an atrial myxoma. In the remaining patient who presented with chronic cor pulmonale, two-dimensional echocardiography demonstrated a motionless ovoid mass with a broad base of attachment to the interatrial septum.