Massive obliterative right heart thrombus presenting with near-syncope.

Intracardiac thrombi are commonly encountered as a complication of a recent myocardial infarction, heart failure, atrial fibrillation, or intracardiac devices. The prevalence of atrial thrombi in the absence of these risk factors is not well-described, but seems to be low. We present a case of a 51-year-old man with a massive mobile thrombus in the right heart extending through the tricuspid valve, diagnosed on echocardiography after presenting with a presyncopal episode.