[Postoperative cardiopulmonary function studies in children and adolescents with pulmonary valvular stenosis...

Cardiopulmonary function studies at rest and during submaximal and maximal exercise were performed in 20 children and adolescents who had undergone valvotomy of a pulmonary valvular stenosis. Maximal oxygen uptake of the patients was 90%, stroke volume 95% of expected values. There was a strong correlation between stroke volume and maximal oxygen uptake. Mean right ventricular systolic pressure at rest was 39 mm Hg and increased to 60 mm Hg at a submaximal load corresponding to 1 1/2 Watt/kg body weight. There was no correlation between right ventricular systolic pressure on the one hand and maximal oxygen uptake, stroke volume and pulmonry valve resistance, on the other hand. It is concluded, that the importance of maximal oxygen uptake as the equivalent of cardiovascular performance capacity and of stroke volume alone as a main parameter of cardiac function may not be overestimated regarding their value in the assessment of the surgical result. A reoperation must be considered when a distinctly elevated right ventricular pressure at rest shows an additional overproportional increase at exercise in the presence of a decreasing stroke volume. This was the case in 3 of our 20 patients.