Physical exercise effect on certain acid-base equilibrium parameters in children with small ventricular septal defects.

Forty-seven children aged from 7 to 16 years were studied: 28 children had small ventricular septum defects and 19 healthy children served as controls. The following acid-base equilibrium parameters were determined in all children: pH, BE, pCO2, metabolic pH and respiratory pH in the arterialized capillary blood taken from the fingertip using an Astrup microapparatus. The determinations were made during three types of physical exercise: normal everyday locomotion and graded exercise raising the heart rate to about 170-180/min and about 190/min. The intensity of the exercise in the step test was calculated from the formula of Nikodemowicz. It was found that metabolic acidosis during these three exercise workloads developed significantly more easily in the children with septum defect than in healthy controls. The same differences were observed in the children with septum defect during the most intense exercise in relation to the exercise of lower intensity.