The dancing thrombus: 4D transesophageal echocardiography in the diagnosis of a pedunculated left atrial appendage thrombus.

It is rare that a left atrial appendage thrombus will grow to the extent that it can prolapse into the left ventricle. We report the case of a large prolapsing left atrial thrombus diagnosed by 3D echocardiography in a patient presenting with a transient ischemic attack.