SUMMARY
Were studied the distribution ratios of ultra-low-frequency, low-frequency and high-frequency components of the heart rate variability (HRV) as an indicator of the state of humoral and autonomic sympathetic and parasympathetic elements in regulation of heart rate in 35 patients with arterial hypertension (AH) aged 59 ± 5 years in the paced breathing test. Evaluation of spectral parameters of HRV was performed with the help of hardware and software «Kardiolab» («HAI-Medica»). Patients were divided into 3 groups according to the degree of power reduction of low-frequency and high-frequency waves of HRV during the transition from spontaneous breathing to paced one: 1st group- less than 5 times; 2nd group – 5–20 times; 3rd group – more than 20 times. Statistical analysis was performed by means of parametric and nonparametric methods using Microsoft Excel 7.0. It was found that in patients with hypertension was observed prevalence of humoral effects in comparison with the sympathetic and parasympathetic parameters. The greater was the contribution of humoral component to the HRV spectrum, the lower was the response of HRV to the respiratory modulation.