Transesophageal Echocardiography Reveals a Missed Right Atrial Aneurysm in a Patient with Atrial Septal Defect and Mitral Valve Prolapse.

Right atrial (RA) aneurysms are rare entities reported in the literature. Affected patients are usually asymptomatic, but sometimes, they tend to present with arrhythmias or even heart failure if big. They may form a nidus for thrombus formation and subsequent thromboembolic complications.