Right atrial appendage aneurysm, or giant right atrial appendage, is extremely rare, with very few cases reported in scientific literature. We sought to systematically review the published cases of right atrial appendage aneurysm in terms of age, sex, clinical presentation, electrocardiography, imaging (chest X-ray, echocardiography, CT/cardiac magnetic resonance), and outcome.

An electronic search for case reports, case series, and related articles published until March 2025 was carried out, and clinical data were extracted and analysed.

Forty-four cases of right atrial appendage aneurysm were identified with a clear male prevalence (68.2%) and commonly presenting in the third decade of life. Palpitation (27.3%) and dyspnoea (18.2%) were the most common clinical presentations, whereas 40.9% of right atrial appendage aneurysm patients were asymptomatic. Electrocardiography was done in 77.3% of the sample. It displayed an atrial arrhythmia (atrial fibrillation or flutter, atrial tachycardia, supraventricular tachycardia) in 31.8%. A chest X-ray was done in 65.9%. Echocardiography was the most common diagnostic modality (93.2%). Right atrial appendage aneurysm diagnosis was confirmed on CT and/or MRI in 79.5%. The mean size of the right atrial appendage aneurysm was 93 × 70 mm. In 12 patients (27.3%), an associated congenital cardiac abnormality was found, mostly in the form of an atrial septal defect/patent foramen ovale (22.7%). Half of the patients (50.0%) were treated surgically, whilst 47.8% were treated medically with close follow-up. One patient experienced right atrial appendage aneurysm reduction in size after atrial septal defect device closure. One death (2.3%) was reported also.

Although very uncommon, right atrial appendage aneurysm can be linked to considerable morbidity. Surgical removal is recommended for patients who are symptomatic.