ABSTRACT
The presence of unrestrictive atrial septal defect is crucial for the survival of patients with certain forms of congenital cardiac defects. The interatrial shunting may be important to augment cardiac output in right-sided obstructive lesions, to relieve elevated Fontan and pulmonary pressures in Fontan failure, to relieve pulmonary hypertension in left-sided obstructive lesions, to decompress the right ventricle in postoperative right ventricular failure, and to improve mixing in transposition of the great arteries and similar physiology.
