1 | INTRODUCTION
Atrial aneurysm is rare in cardiac anomaly, most of which are left atrial aneurysms in adults. Right atrial appendage aneurysms (RAAAs) are extremely rare compared to other cardiac aneurysms, especially for infants and pediatric population. According to the literature, no more than 25 cases have been reported so far, among which only 3 cases are infants or neonates.1,2 A systematic review published in 2014 found that the highest morbidity of RAAAs was in the third decade of life, with cases noted from the perinatal period to 72 years of age.3 RAAAs usually involve free walls and atrial appendages, most have congenital origins and develop in the course of pregnancy.2,4 Generally, patients with RAAA are usually asymptomatic and are diagnosed incidentally or until they present some clinical symptoms like arrhythmia or dyspnea.5 Pulmonary thromboembolism is a common complication due to blood stasis in the aneurysm.6However, there is no guideline for the treatment of this condition, and surgical resection is safe and can be performed through sternotomy with or without cardiopulmonary bypass for symptomatic patients.2,5 Here, we reported an infant with a giant RAAA and severe symptoms who underwent surgical resection of the aneurysm.