Exercise cardiorespiratory function in adolescents with pectus excavatum. Observations before and after operation

Abstract

We studied 12 children with pectus excavatum (mean age, 13.8 years) using pulmonary function and exercise testing. Eight patients had surgical repair and were studied before and after repair. Four patients did not have repair and were tested twice. The degree of chest wall deformity in the two groups was similar. All patients reached 86% or more of their maximal predicted heart rate with exercise. Total lung capacity decreased 8% (p less than 0.01) after operation. In the nonoperated control group, total lung capacity was similar during both studies. The ratio of ventilation at maximal exercise to maximal voluntary ventilation was 68% +/- 12% before and 66% +/- 9% after operation in the operated group and 69% +/- 18% and 79% +/- 30% at two studies in the nonoperated group (nonsignificant changes). Maximal oxygen uptake was 36.1 +/- 4.4 ml/kg/min preoperatively and 38.1 +/- 8.1 postoperatively and 41.2 +/- 7.3 ml/kg/min and 43.0 +/- 6.9 on two studies in the nonoperated group (nonsignificant changes). Cardiac output and stroke volume increased appropriately with exercise both before and after operation. Operation had no physiologically significant effect on the cardiorespiratory response to exercise. Slight changes in cardiorespiratory function occurred in both operated and nonoperated subjects. These results emphasize the importance of studying patients before and after operation and of using a control group.