Exercise tolerance after repair of tetralogy of Fallot.

Twelve patients who had undergone complete repair of tetralogy of Fallot at ages ranging from 8 to 27 years were studied for exercise tolerance several years later. Work performance ranged from 58 to 130% of that predicted. Increased physiological dead space and alveolar-arterial Po2 difference at exercise suggested pulmonary vascular disease, which was confirmed in 1 patient by pulmonary angiography. Excercise tolerance decreased with increasing age at time of repair, underlining the desirability of early corrective operation.