TREADMILL ERGOMETRY FOR EVALUATION OF PHY SICAL WORKING CAPACITY IN HEALTHY-CHILDREN AND CHILDREN WITH HEART-DISEASE

Background: In order to evaluate the physical working capacity of chil dren a maximal treadmill test was developed and tested in 82 normal an d 26 children with congenital heart disease. Method: Starting with a g rade of 0% and a speed of 2.5 km/h the work load was increased progres sively by increments of 3% (grade) and 2.5 km/h (speed) for 2 minute i ntervals, until a maximum of 9 steps was reached or the subject was un able or unwilling to continue. Heartrate, systolic blood pressure, and the current plasma-lactate concentration were measured after each ste p, The lactate performance curve was assessed as well as the effective test duration. Results: In the group of healthy children the expected differences in test duration, heart rate, and systolic blood pressure were observed according to age and sex. The lactate concentrations af ter the test indicated a metabolic exhaustion, The lactate performance curve was shown to be a reliable parameter indicating different cardi ac capacity dependent on the child's constitution and physical fitness . Conclusion: Even children heart disease can manage maximal treadmill test following our protocol, Compared to the more commonly used subma ximal bicycle ergometry, our treadmill test is a child adapted alterna tive more within every day experience.