CARDIOGRAPHIC CHANGES IN ACUTE HYPOXIA AFTER INTERMITTENT HYPOXIC TRAINING IN HUMANS

Abstract

One of the important areas of research in physiology and medicine is the impact of intermittent hypoxic training on human resistance to exogenous and endogenous environmental factors. Special attention is also paid to cardiac activity. The aim of the paper is to examine the nature and conjugation of human heart bioelectrical processes in acute hypoxia after intermittent hypoxic training. Materials and methods. A 20-minute test with acute hypoxia (AH – 12.3 % O2) was conducted on 29 males, aged 20.2±0.31, at different periods after 16-day-hypoxic training. Blood saturation (SpO2%), amplitude and time ECG parameters were determined. Results. At rest, at certain periods after hypoxic training, we observed an increase in R-R (Day 1, p=0.020), Q-T (Day 1, p=0.005; Day 16, p=0.043) and a decrease in P-Q (Day 7, p= 0.016) compared to the control. In case of acute hypoxia there was a decrease in P1II (Day 1, p=0.019; Day 7, p<0.001; Day 16, p=0.003), P-Q (Day 1, p=0.025; Day 7, p =0.002), PQc and QTc (p<0.001), but an increase in T1II (Day 1, p<0.001; Day 7, p=0.005; Day 16, p=0.010), R-R (Day 1, p<0.001; Day 7, p=0.029; Day 16, p=0.002) and Q-T (Day 1, p<0.001; Day 7, p<0.001; Day 16, p<0.001) compared to the control. According to the period after hypoxic training, we observed the dominance of the factor load R-R, Q-T and P1II, T1II, as well as an increase in the canonical correlation of P1II, RII and T1II with R-R and Q-T. Conclusion. Intermittent hypoxic training leads to an increase in R-R duration, electrical ventricular systole and a decrease in atrioventricular conduction at rest. In case of acute hypoxia in the period after hypoxic training, all ECG parameters (besides maximum ventricular depolarization) change significantly compared to the control. The paper discusses the factorial significance and the degree of conjugation of bathmotropic and dromotropic cardiac processes.