Left ventricular pseudo-aneurysm must be distinguished from a left ventricular aneurysm.
A pseudo-aneurysm (or false aneurysm) arises post-myocardial infarction or post chest trauma, and is consequent to rupture of the myocardial free-wall, which occurs days post infarction, and fortiutously becomes limited by a pericardial adhesion (without this, myocardial rupture is usually rapidly fatal). Thus, the pseudo-aneurysm wall consists only of epicardium, pericardium and haematoma. Left ventricular pseudo-aneurysms remain at risk of rupture, more so shortly after the precipitating event. They are commonly posterolateral.
In contrast, a left ventricular aneurysm is a more stable acquired, or rarely congenital pathology. These true aneurysms of the ventricular wall are bounded by scarred myocardium and are commonly a late complication of large transmural infarcts Complications of ventricular aneurysms include mural thrombus, arrhythmias, and heart failure; rupture of the tough fibrotic wall is not a concern. They tend to be anterolatera or apical, and often calcify with time.
It is rarely seen on chest x-ray, since smaller, with a wider neck than pseudo-aneurysm.