Congenital aneurysm of the right atrium

Congenital aneurysm of the right atrium is described in a 1-year-old girl who presented with cardiomegaly and symptoms of paroxysmal supraventricular tachycardia. Echocardiography and cineangiography both established the definitive diagnosis and surgical resection was successful. The rarity of this condition is pointed out and its main features outlined.