Congenital Left Atrial Appendage Aneurysm: The Role of Prenatal Fetal Echocardiography in Early Recognition.

Congenital left atrial appendage aneurysm (CLAAA) is a rare congenital cardiac anomaly that can lead to significant cardiac and systemic complications. Early recognition through fetal echocardiographic scanning is crucial for establishing a comprehensive management plan prior to delivery, including baseline postnatal assessment and close follow-up to allow timely surgical resection before the development of severe local or systemic complications such as heart failure or thromboembolism. We report a case of giant CLAAA initially suspected as a fetal cardiac mass on routine obstetric ultrasound, which was subsequently characterized in detail by fetal echocardiography at our institution. The diagnosis was later confirmed postnatally by transthoracic echocardiography and computed tomography. When the patient developed atrial tachycardia, surgical resection of the aneurysm was performed successfully before the onset of any disabling systemic complications.