Left Ventricular Aneurysms

A left ventricular aneurysm is a focal outpouching from the diastolic contour of the heart associated with akinetic or dyskinetic wall motion. The usual trabeculations are absent, and the wall of the aneurysm is usually smooth. Left ventricular aneurysm are present in about 10% of patients with coronary artery disease, usually associated with severe disease involving more than one vessel.

Left ventricular aneurysms can be classified as functional, true (anatomic), or false. Unique findings of each are underlined.

• Functional: Also known as a forme fruste of the true aneurysm. The contour is normal during diastole, but bulges out during systole. Occurs because of spasm, ischemia, or infarction and may be reversed following revascularization. The wall of the aneurysm is left ventricle with scar with or without myocardial fibers. Thrombus formation is rare. Calcification is never seen. Rupture is rare.
• True (anatomic): A bulge is seen during both systole and diastole. Location is typically anterolateral, apical, or septal. The mouth of the aneurysm is as wide as or wider than its maximal diameter. The wall of the aneurysm is left ventricle with scar with or without myocardial fibers. Thrombus and calcification are common. Rupture is rare (less than 5% of cases).
• False: A bulge is seen during both systole and diastole. Typically occurs along the inferior and anterolateral walls. The mouth of the aneurysm is typically less than 50% of its maximal width. The wall of the aneurysm is the pericardium. Thrombus and calcification are uncommon. It has a propensity to expand and rupture (45% of cases). Contrast material may not fill the aneurysm until late in systole and opacification of the sac may persist after contrast has left the left ventricle. Differential considerations include congenital diverticula (smaller and occur at the apex), African cardiomyopathies (different clinical course and lack of coronary artery disease).

References

Miller SW and Boxt LM. Chapter 7: Ischemic heart disease. in Cardiac Imaging, the Requisites Third edition, Miller SW, Boxt LM, and Abbara S, eds. Mosby 2009.