Five chambered heart: case of a huge left atrial appendage aneurysm

Aneurysmal enlargement of the left atrial appendage is an extremely rare pathology and can predispose to adverse events, including cardiac arrest, respiratory distress, arrhythmia, heart failure, systemic thromboembolism, or rupture. It is usually diagnosed incidentally or after the occurrence of atrial tachyarrhythmias or thrombotic events in the second to fourth decades of life. We describe a rare case of a symptomatic giant congenital left atrial appendage aneurysm (LAAA) in a 26-year-old man presenting with neurologic event, in whom surgical resection of the aneurysm was successfully performed. This is the largest LAAA reported in the literature so far. •Congenital left atrial appendage aneurysm (LAAA) is an extremely rare anomaly.•We describe the largest congenital LAAA reported in the literature, to date.•Surgical exposure found a huge and thin-walled LAAA measuring 15×12×8 cm.•In presented case, surgical resection of the aneurysm was successfully performed.