Giant Left Atrial Appendage Aneurysm or Pericardial Effusion: A Misleading Appearance on Echocardiography and a High Risk of Rupture

Left atrial appendage (LAA) aneurysm or giant LAA is an uncommon condition. It could be discovered incidentally during echocardiography examination or in symptomatic patients presenting with tachycardia or embolic events. The giant LAA is a serious condition with a high embolic risk that can cause respiratory distress and even cardiac arrest in children. A conservative surgical approach based on resection of the LAA is recommended and is mostly safe. We report the case of a four-year-old girl presenting with a symptomatic giant LAA removed successfully. The echo-cardiographer must be aware of its appearance mimicking a pericardial effusion and focus on its possible association with other congenital lesions. There are several therapeutic strategies, all with proven efficacy and safety.