Fig

A cross section through the heart reveals a ventricular aneurysm with a very thin wall at the arrow. Note how the aneurysm bulges out. The stasis in this aneurysm allows mural thrombus, which is present here, to form within the aneurysm.
LV aneurysm complicating MI


There has been a previous extensive transmural myocardial infarction involving the free wall of the left ventricle. Note that the thickness of the myocardial wall is normal superiorly, but inferiorly is only a thin fibrous wall. The infarction was so extensive that, after healing, the ventricular wall was replaced by a thin band of collagen, forming an aneurysm. Such an aneurysm represents non-contractile tissue that reduces stroke volume and strains the remaining myocardium.
Lt ventricular aneurysm complicating healed MI