Left ventricular aneurysms and pseudoaneurysms are two complications of myocardial infarction (MI) that can lead to death or serious morbidity.
A left ventricular aneurysm (LVA) is most commonly the result of MI, usually involving the anterior wall. Other causes of LVA include hypertrophic cardiomyopathy and Chagas disease, both of which can lead to the formation of an apical aneurysm. The aneurysm may be asymptomatic or present as heart failure, sustained ventricular tachyarrhythmias, or arterial embolism (image 1 and image 2). (See "Types and pathophysiology of obstructive hypertrophic cardiomyopathy", section on 'Apical HCM' and "Clinical manifestations and diagnosis of Chagas heart disease".)
A pseudoaneurysm, or false aneurysm, develops after an acute MI which is complicated by a ventricular free wall rupture that is contained by localized pericardial adhesions. As described below, the contained cavity is characterized by a narrow neck communicating freely to the left ventricle and a tendency to expand and rupture (image 3). These features are distinctly uncommon with a true LVA, which generally does not rupture after it forms.
LEFT VENTRICULAR ANEURYSM
The definition of a LVA remains controversial. For the purpose of this topic review, a true LVA is defined as a well delineated, thin, scarred or fibrotic wall (image 4), devoid of muscle or containing necrotic muscle, that is a result of a healed transmural MI. The involved wall segment is either akinetic (without movement) or dyskinetic (with paradoxical ballooning) during systole (image 5), and collapses inward when the ventricle is fully vented during surgery. Aneurysms of the apex and anterior wall are more than four times as common as those of the inferior or inferoposterior walls.
Incidence — It was previously estimated that LVA develops in up to 30 to 35 percent of patients with Q wave MI [1,2]. However, the incidence of this complication is decreasing, and currently is about 8 to 15 percent in such patients . This change is related to the introduction of major improvements in the management of patients with acute MI. (See "Overview of the acute management of ST elevation myocardial infarction".)