Giant Isolated Congenital Left Atrial Appendage Aneurysm Complicated by Thrombus: Multimodality Imaging Assessment.

BACKGROUND

Left atrial appendage aneurysm (LAAA) is a rare cardiac malformation; giant forms of LAAA complicated by thrombus are exceptionally uncommon.

CASE SUMMARY: A 36-year-old woman with atrial flutter, palpitations, and dyspnea was evaluated after chest radiography showed cardiomegaly and computed tomography revealed a mediastinal mass. Cardiac magnetic resonance confirmed a giant LAAA measuring 11 × 6 × 1 cm with a thrombus measuring 21 × 25 × 24 mm, producing a mass effect and contacting the mid-left anterior descending artery. Surgical resection was performed, with remission of atrial flutter, resolution of symptoms, and clinical stability at 6-month follow-up.

DISCUSSION: LAAA is linked to arrhythmia, embolic events, and compression. Multimodality imaging defines anatomy and thrombus, while surgery is the treatment in complicated cases.

TAKE-HOME MESSAGES: LAAA carries risks of arrhythmia, thromboembolism, and compression. Multimodality imaging enables diagnosis and thrombus detection. Surgery provides symptom relief, arrhythmia remission, and prevention of complications.