Application of Holter electrocardiography to an exercise test for heart function is useful in the group examination of school children.
The circulatory responses to a step test among obese boys and girls and control were as follows:
1. Four cases of arrhythmia were detected, of whom 2 cases were discovered during exercise. ST-segment depression of 0.1mV or more during and after exercise was recognized in 29 cases, 27 of the junctional- and 2 of the sagging slope, with a higher percentage in obese girls than in normal girls.
2. Serial ECG records during the procedure, performed for all children with the same single-step test, showed differences in the circulatory responses among the test groups. The load was estimated to be 76-86% of the maximal heart rate predicted by Cummings, with obese and girl groups being higher than other groups. The comparison revealed that the heart rate (HR) responses to exercise done by the boys increased faster than those by the girls at 1 minute after exercise. There were differences between obese and control and between boys and girls in HR at recovery, and also in HR before and 4 minutes after exercise between two sexs, which findings agree with other reports.
3. Concerning anthropometric factors, either the skinfold thickness or the obesity index was related to the HR at the peak of the exercise as well as immediately after it and to the half time. By contrast, the arm muscle diameter was found unrelated to the HR.
Using this method, applied these combination of Holter ECG and step test to a group examination, we got ECG data for 254 subjects, 97.5% of which were suitable for analysis. We found this method to be effective for detecting ECG changes and for determining HR responses to exercise. This method is safe, simple, and inexpensive and is applicable to examinination not only for school children but also for different population groups, for the estimation of circulatory responses.
