The Success of Heart Rate Variability Biofeedback Parameters in Persons with Different Levels of Blood Pressure
Objective. The aim was to determine the nature of cardiovascular reactions during a single session of heart rate variability (HRV) biofeedback in order to increase vagal effects on heart rhythm in patients with different initial levels of blood pressure (BP). Participants and methods. 33 people with normal blood pressure (group I), 20 people with uncorrected arterial hypertension (AH) grade 1-2 (group II) and 22 people with AH grade 1-2 taking antihypertensive drugs (group III) were observed. The parameters of heart rate variability (HRV), BP and pulse oximetry in the initial stage, during a single HRV biofeedback session and after this session in order to increase the total power of the HRV spectrum (each stage was 5 min). Results. In patients of group II low success of HRV biofeedback session, a high sympathetic reactivity and reduced oxygen blood saturation were determined. A reactivity of vagal mechanism is more pronounced in persons of group III than in those of group II. It is reflected in a significant increase in their total power of the HRV spectrum compared to the initial values and in uptrend saturation levels during the biofeedback session. Conclusions. The ability to HRV biofeedback in order to increase the total power of the HRV spectrum for standard short recording (5 min) can be seen as a test to determine the safety reserves of vagal autonomic cardiovascular regulation in persons with increased blood pressure.