Exercise performance in children and adolescents after surgical repair of tetralogy of Fallot.

Cardiopulmonary function studies at rest and during submaximal and maximal exercise were performed in 21 children and adolescents who had undergone surgical correction of tetralogy of Fallot. Maximal oxygen uptake of the patients was 84.6% of healthy peers matched for age and height. The reduced aerobic capacity can mainly be attributed to a reduction in stroke volume. In the presence of a reduced stroke volume normal cardiac output during submaximal exercise was achieved and maintained by an increase in heart rate. During maximal exercise, however, the heart rate did not exceed that of the healthy controls and the results for the children in this series are about 20% higher than those reported in the literature for adults who had undergone surgical repair of a tetralogy. Persistent impairment of cardiac function in patients with tetralogy of Fallot who have undergone corrective surgery may represent a residual outflow tract obstruction in the right ventricle, impaired function of the left ventricle or the result of restricted physical activity.