False aneurysms of the left ventricle following myocardial infarction

In 2 cases myocardial infarction was complicated by the occurrence of a left ventricular false aneurysm. In the first case the aneurysm involved the anterolateral portion of the left ventricle; in the second the infarct was in the ventricular septum, and the resulting false aneurysm in the epicardium was basal in situation and extended posterior to each atrium. Whereas a true aneurysm of the left ventricle following myocardial infarction represents a bulging of a weakened left ventricular wall, a false aneurysm occurs as a result of rupture of the left ventricular wall. In contrast to a true aneurysm of the left ventricle, a false aneurysm has a wall consisting of fibrous tissue and is sharply demarcated from the cavity of the left ventricle. The rarity of false left ventricular aneurysms is related to the usual occurrence of fatal hemopericardium following rupture of the left ventricular wall.