Coronary neovascularity related to a left ventricular mural thrombus.

Thirty-six patients with the angiographic diagnosis of left ventricular mural thrombus were reviewed. All had a history of myocardial infarction. In 9 of these patients (25%), coronary neovascularity was related to a left ventricular mural thrombus. Although no relationship was found between either the size of the mural thrombus or the duration of illness and the neovascularity, the incidence of neovascularity was low in a group taking anticoagulants. Arteriographic characteristics of the neovascularity in the present cases are: 1) In all cases, the neovascularity arose from the left anterior descending coronary artery. 2) The neovascularity consisted of a hypervascular region in the same location as the mural thrombus. It was observed as a dense mass of small vessels penetrating the left ventricle in a form resembling a toothbrush. 3) The neovascular region had no veins and it extended through the narrow gap of the thrombus to communicate with the left ventricle. Histological studies were consistent with coronary arteriography. The demonstration of neovascularity by coronary arteriography suggests either that the thrombus is relatively new or that a new thrombus is further organized on the old thrombus. This seems to be useful information from a therapeutic viewpoint.