Нeart rate variability of children aged 8-11 with deprivation of auditory function
Authors: Koval Y. V. , Yukhymenko L. I. , Khomenko S. M. 
Published: August 2021

ntroduction.Currently, there are quite a number of publications on the peculiarities of heart rate in children with hearing impairments. However, such studies were conducted with individuals who had varying degrees of deafness and virtually did not examine children with congenital deafness.Children with congenital deafness are likely to have significant changes in cardiovascular system (CVS) indicators compared to their healthy peers. Purpose.The aim of the study was to elucidate the mechanisms of heart rate regulation in children with deprivation of auditory function during active orthostatic testing. Methods. The study involved 15 children: boys (7 individuals) and girls (8 individuals) aged 8-11 with congenital deafness and 17 almost healthy peers. Cardiorhythmograms were recorded with spectral characteristics of heart rate: (VLFms2, less than 0.05 Hz), low (LFms2, 0.05--0.4 Hz) frequencies; the ratio of LF/HF was considered.Results.The results of the study suggest that a group of childrenwith hearing deprivation in all indicators of spectral analysis of HRV had a much lower reactivity of the CVScompared to their healthy peers. The LF indicator did not change significantly, and therefore the sympathetic link of regulation did not play a significant role. However, the contribution of the parasympathetic system, which can be judged by HF, was significantly reduced in both groups. Thus, we can assume that the regulation of blood circulation was due to reduced activation of the parasympatheticlink with constant sympathetic. This feature is indicated by the indicator of vagosympathetic balance of the LF / HF ratio. Its changes reached quite significant values: 87.5% in deaf and 262.5% in healthy children. This indicates the leading role of the sympathetic system in the regulation of heart rhythm in children 8-11 years during orthostasis. However, the differences in the reactivity of the CVSof representatives of different groups indicated a less pronounced degree of activation of this link in the regulation of children with derivation of auditory function.The ratio of the length and width of the autocorrelation cloud (L / W) indicated a similar dependence. The dynamics of this indicator in the direction of increase may indicate a change in the intensity of the autonomic circuit regulation of cardiac activity. 202159In healthy subjects, these changes occurred with a greater degree of activation of central regulatory mechanisms than in children with hearing impairments.Because TP is an almost complete physiological analogue of SDNN, its decrease during orthostasis in children with hearing deprivation by 20.1% and 44.2% in healthy people indicates that the total effect of central regulation mechanisms decreases.Originality.Currently, there are virtuallyno data on reactive changes in the cardiovascular system of children with hearing impairments to postural gravitational loads, especially in relation to children with congenital deafness. This is important given that information about the reactions of thecardiovascular system of children with hearing impairments will allow you to adjust the exercise, choose the optimal motor mode and predict possible deviations or pathologies.Conclusion.Children with the deprivation of auditory function are characterized by more pronounced maladaptive responses of the cardiovascular system to orthostatic load than their healthypeers. Central regulatory mechanisms in deaf children have less pronounced activation compared to healthy children. At orthostatic test, in both groups of subjects, regulation of blood circulation is carried out mainly at the expense of a parasympathetic link of an autonomic nervous system.Keywords. deprivation of auditory function, heart rate variability, spectral analysis