Left Atrial Appendage Aneurysm—A Rare Anomaly with an Atypical Presentation

Left atrial appendage aneurysm (LAAA) is a rare condition caused by congenital dysplasia of the atrial muscles. Patients usually present with atrial tachyarrhythmias as a result of ectopic foci of atrial rhythm generation or systemic thromboembolism. We report a case of a 38-year-old Native American female presenting with 1-month history of cough, in sinus rhythm, and found to have a large cyst-like structure next to the left ventricular lateral wall on transthoracic echocardiography. This structure was later confirmed as a LAAA on cardiac magnetic resonance imaging. Patient underwent aneurysmectomy without any complications.