Imaging reveals a fifth heart chamber: Diagnosing and treating a massive left atrial appendage aneurysm

Fig. 1. Posterior-anterior chest radiography showing a prominent left heart border.

Fig. 2. Computed tomography and transthoracic echocardiography demonstrating the giant left atrial appendage aneurysm. The following section of the CT shows a significantly enlarged fifth heart chamber representing the giant left atrial appendage aneurysm (A). (B and Fig. 3B) represent the echocardiogram findings in these patients. (B) demonstrated the presence of the left atrial appendage aneurysm while (C) shows the resolution of the aneurysm following resection. LA; Left atrium, RA; Right atrium; RVOT; Right ventricular outflow tract, AV; Aortic valve, *; Left atrial appendage aneurysm, RV; Right ventricle, RA; Right atrium, LA; Left atrium, LV; Left ventricle, *; left atrial appendage aneurysm.

Fig. 3. (A) the giant left atrial appendage aneurysm is visualized. Following the resection of the aneurysm, a large indentation was observed on the myocardial wall due to the chronic compression caused by the left atrial appendage aneurysm. This finding is illustrated in (B).