Vegetative Provision of the Heart Functional Reserve of Adolescents of Different Medical Groups

Abstract

Topicality. Physical performance of adolescents of different medical groups varies in wide range. The division of pupils into medical groups according to the Rufier’s index does not reflect the level of their physical performance. The Aim of the Study is to investigate the relationship between autonomic support of cardiac activity, physical performance and functional heart reserve of adolescents of different medical groups. Material and Methods of Research. 140 schoolchildren of 7–8th gra- des aged 12–14 years were examined (average age 12,9±0,65 years). Among them 58 boys (mean age 12,9±0,7 years) and 82 girls (mean age 13,0±0,6 years). Physical performance (PWC₁₇₀), cardiovascular function (Rufier index), heart rate variability (HRV) were studied. Statistical analysis was performed using the application package Statistica-v.10.0. Results. In the study of autonomic support of cardiac activity, significant differences were found between the main and special medical groups on the following indicators of HRV at rest: LF norm, n.u., HF norm, n.u., LF/HF, USD, % LF. The mean values 30:15 ratio did not differ between different medical groups. And their average values were in the range of 1,0– 1,25 USD, which characterizes the deterioration of the functional state of the body in all medical groups. The balance of sympathetic and parasympathetic divisions of the ANS, according to the average data of heart rate increase in orthoprobe, was within the physiological norm (18–27 %) and did not differ between different medical groups. Conclusions. At rest, there is a predominance of activity of the sympathetic link in the modulation of heart rate of adolescents of a special medical group in comparison with the main. However, in active orthostatic testing there are no differences between the indicators that characterize the state of autonomic regulation of cardiac activity and the reactivity of the sympathetic and parasympathetic divisions of the autonomic nervous system.