Giant right atrial aneurysm in a symptomatic adult—a rare congenital malformation

Aneurysms of the right atrium (RAA) are a rare congenital malformation with about 20 cases reported world-wide and may occur in any age group from foetus to adults. In symptomatic cases, it may be associated with pulmonary embolism and atrial rhythm disturbances. We report on a 56-year-old man who presented with acute chest pain. In his past history an Ebstein's anomaly of the tricuspid valve had been diagnosed 40 years ago. At that time he was symptomatic with atrial fibrillation and had received repeated external cardioversions. In 1998, pulmonary embolism was diagnosed and he was put on oral anticoagulation. Transoesophageal echocardiography (Panel A) showed a 12 to 7 cm right atrial enlargement in front of a normal sized right atrium and right ventricle. The tricuspid valve was normal in morphology and function. The entrance from the right atrium to the RAA was 2 cm in the vertical and 4.6 cm in the horizontal plane. Spontaneous echo contrast was present within the RAA as a sign of low flow. Multi-slice computed tomography (CT) confirmed the diagnosis of the huge RAA (Panels B and C). The wall of the RAA appeared paper-thin. There was no evidence for thrombus formation within the aneurysm. As the patient had been symptomatic with arrhythmia and pulmonary embolism for many years, the indication for the operative resection was established. After opening the chest in the operation room, the paper-thin wall of the aneurysm (Panel D) could be resected with the help of normothermic cardiopulmonary circulation.