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

Sep 29, 2026

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Congenital left atrial appendage aneurysm (CLAAA) is a rare congenital cardiac anomaly that may cause major cardiac and systemic complications. Early recognition through fetal echocardiographic screening supports timely planning before delivery, including baseline postnatal assessment and careful follow-up. This enables early surgical intervention to prevent severe outcomes such as heart failure or thromboembolism. The report describes a giant CLAAA first suspected prenatally and characterized by fetal echocardiography and later confirmed after birth, with successful resection after atrial tachycardia.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages8

Reading Time20 min

AccessFree to download

Introduction

Case Presentation

Prenatal findings

Fetal echocardiography

Delivery and postnatal evaluation

Discussion and outcome

Review began 11/01/2025 Review ended 11/16/2025 Published 12/07/2025 © Copyright 2025 Algonaid et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CCBY 4.0. , which permits unrestricted use , distribution , and reproduction in any medium , provided the original author and source are credited. DOI: 10.7759/cureus.98614 Open Access Case Report Congenital Left Atrial Appendage Aneurysm: The Role of Prenatal Fetal Echocardiography in Early Recognition Omer A. Algonaid 1, Rana S. Alaskar 1 , Omar Altamimi 1, Asma A. Alsultan 2 1. Pediatric Cardiology, King Fahad Medical City, Riyadh, SAU 2. Pediatric Cardiology, King Fahad General Hospital, Riyadh, SAU Corresponding author: Omer A. Algonaid, [oalgonaid@kfmc.med.sa](oalgonaid@kfmc.med.sa) Abstract 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. Categories: Cardiology, Cardiac/Thoracic/Vascular Surgery, Pediatrics Keywords: atrial appendage aneurysm, atrial tachycardia, congenital cardiac surgery, fetal echocardiogram, systemic thromboembolism Introduction Congenital left atrial appendage aneurysm (CLAAA) was first described by Parmley in 1962 during a surgical procedure [1] and the diagnostic criteria’s where described as following: (1) origin from an otherwise normal left atrium (LA), (2) well-defined communication with the LA, (3) position within the pericardium, and (4) distortion of the left ventricle free wall by the aneurysm [2] . CLAAA has been reported in the literature worldwide, mainly through small retrospective studies or case reports, with variable descriptions [2-4]. Oneof these studies reached more than 80 cases [5] . The majority of these left atrial appendage aneurysm (LAAA) cases are asymptomatic. Nevertheless, symptoms like palpitations (43%), dyspnea (22%), and/orthromboembolic phenomenon (11%) are reported. Many factors were mentioned as a risk for systemic thromboembolism. However, only the tachyarrhythmia had a statistically significant association with such a complication [5] . Only two cases of giant CLAAA were reported in Saudi Arabia. The first case was a two-month-old with pneumonia, who also had an abnormal mass in the chest X-ray that blurred the left heart border and caused left lung collapse. These X-ray findings mandate further evaluation by echocardiography and computed tomography, which revealed the full diagnosis of LAAA with subsequent pathological confirmation after surgical resection [6] . The second case was a four-month-old, investigated for an incidentally detected murmur, where echocardiography diagnosed a giant LAAA that was confirmed by computed tomography scan [7] . Case Presentation A 32-year-old gravida 2, para 1 mother underwent a routine prenatal visit during which fetal ultrasonography revealed a single cystic mass adjacent to the left side of the heart, measuring 40 × 31 mm (Figures 1A-1B) . How to cite this article Algonaid O A, Alaskar R S , Altamimi O , et al. (December 07 , 2025) Congenital Left Atrial Appendage Aneurysm: The R

FAQs

Why is early recognition of CLAAA important?

Early recognition enables comprehensive management planning before delivery, including baseline postnatal assessment and close follow-up. It also helps allow timely surgical resection to prevent severe complications such as heart failure or thromboembolism.

How was the suspected fetal mass evaluated and confirmed in this case?

The mass was first suspected on routine obstetric ultrasound, then characterized with fetal echocardiography. Postnatal confirmation was achieved using transthoracic echocardiography and computed tomography.

What clinical event led to surgery, and what was the result?

When the patient developed atrial tachycardia, surgical resection of the aneurysm was performed successfully. The surgery occurred before disabling systemic complications developed.

Sep 29, 2026

Uploaded by Callum