False aneurysms of the left ventricle. Identification of distinctive clinical, radiographic, and angiographic features.

False aneurysms of the left ventricle were observed in 14 patients. They were caused by obstructive coronary arterial disease with resultant myocardial infarction in 11, bacterial endocarditis in 1, a knife wound in 1, and disruption of a ventriculotomy in 1. Most of them extended posteriorly on the lateral radiograph, as opposed to the usual anterior position of true aneurysms. Enlargement was frequently observed on sequential studies. Angiography usually demonstrated involvement of the diaphragmatic or posterolateral segment due to occlusion of the right coronary artery; in contrast, true aneurysms are apical or anterolateral and are due to occlusion of the left anterior descending artery. The frequency of rupture of false aneurysms points up the importance of distinguishing them from true aneurysms.