Time–Frequency Analysis of Variability in External Respiration and Heart Rate in Humans during Exercise.

Autor: Grishin, V. G., Grishin, O. V., Nikultsev, V. S., Gultyaeva, V. V., Zinchenko, M. I., Uryumtsev, D. Yu.
Zdroj: Biophysics; Aug2022, Vol. 67 Issue 4, p605-611, 7p
Abstrakt: Very low frequency (VLF) oscillations in parameters of the oxygen transport system (OTS) were studied at rest and during light physical exercise on a bicycle ergometer. Nine healthy subjects (five males and four females) aged 26–58 years participated in the study. The following indicators were recorded by the breath-by-breath method in a 30-min test: end-tidal oxygen, end-tidal carbon dioxide, respiratory rate, and tidal volume. The heart rate was simultaneously recorded using a PoliSpectr 8 ECG system. Pulmonary gas exchange was assessed by the rate of O2 absorption from the inhaled air. The intensity of pulmonary gas exchange during exercise was three times higher than at rest. Time–frequency analysis was used to study quasi-periodic oscillations. The results confirmed the stability of periodic oscillations in the VLF range during physical exercise. Exercise increased the frequency characteristics of all OTS parameters by 28–63%. The variability in the VLF range persisted in spite of the fold increase in the mean values of external respiration and metabolic parameters and the additional effect of cyclic exercise on a bicycle ergometer. The results confirm the hypothesis that synchronization of slow oscillations of RR intervals in the ECG signal with oscillations in pulmonary ventilation and gas exchange signals is a regular phenomenon. The respiratory and circulatory systems were assumed to form a united cyclic circuit of autoregulation (self-organization), the system-forming function of which is to support metabolism at the cell level or the level of the whole human body. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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