How do you differentiate a congenital from an acquired left atrial appendage aneurysm?
Congenital aneurysms of the left atrium have the following features: The atrial cavity and the aneurysm must show clearly defined communication. The aneurysm must originate from a normal atrial chamber The aneurysm should be intrapericardial in location with resultant compression and distortion of the left ventricle. (3)
The heart shows marked asymmetric enlargement, more on the left side.
No double density is appreciated and the carinal angle shows normal angulation (less than 90 degrees). On the lateral view, the left main stem bronchus is not displaced posteriorly. These findings make an enlarged left atrium and pericardial effusion, a less likely diagnosis.
The left hemidiaphragm and costophrenic sulcus are obscured. Vertical density in the left retrocardiac area may represent atelectasis.