Congenital intrapericardial aneurysms of the left atrium.

A patient with congenital intrapericardial aneurysm/diverticulum of the left atrium diagnosed preoperatively is described. A review of the 16 previously reported cases revealed that the majority of the patients present with palpitation and are found to have an abnormal cardiac shadow on chest radiography, as did this patient. The aneurysm appears to cause systemic emboli and paroxysmal or persistent atrial tachyarrhythmias which are often resistant to medical therapy. The presence of the aneurysm is suggested by an abnormal contour of the left cardiac border in the postero-anterior chest radiograph and this can be confirmed by angiocardiography. Surgical excision of the aneurysm is indicated in all patients to prevent the occurrence or recurrence of systemic emboli and atrial arrhythmias. Our patient has remained free of symptoms since her operation 14 months ago.