 - Thrombus formation within a coronary vessel is the acute precipitating event in most unstable ischemic coronary syndromes, as documented by angiographic and pathologic studies . Among patients with sudden death due to coronary thrombosis, the thrombi typically have a layered appearance indicative of episodic growth. Episodic growth may alternate with intermittent fragmentation of the thrombus, leading to distal embolization of both thrombus and platelet aggregates and microinfarction. 