Aneurysm of the atrial septum in tricuspid atresia: diagnosis during life and therapy.

Massive aneurysmal dilatation of the foramen ovale was diagnosed angiocardiographically in a patient with tricuspid atresia. The angiographic findings are distinct for this condition, and the pathogenesis appears to be related to a restrictive atrial communication in the patient with obligatory right to left shunting at atrial level. The anatomic potential for atrial restriction in the patient with tricuspid or pulmonary atresia, intact ventricular septum and diminutive right ventricle necessitates balloon atrial septostomy at the initial diagnostic cardiac catheterization. In the patient with aneurysmal dilatation of the foramen ovale, satisfactory decompression may be achieved by Blalock-Hanlon atrial septectomy, open atrial septectomy, or, possibly, balloon septostomy.