Following a myocardial infarction (MI), the contractility of the affected muscle is abnormal and often leads to circulatory stasis. The damaged endocardium, in the presence of stasis, creates a thrombogenic surface and easily leads to the formation of a mural thrombus. The thrombus can embolize and cause further problems downstream. The image shows a large mural thrombus attached to the right ventricular wall. The patient was a 58 y/o male with severe atherosclerosis-induced narrowing of the major coronary vessels who suffered MI.