System analysis of heart rate variability, hemodynamics, and bioelectrical activity of the human brain at moderate altitudes

Heart rate variability (HRV), hemodynamics, cerebral α rhythm, and systemic relations between them have been investigated in 35 normal human subjects at the age of 37.2 ± 3.8 years. The results of comprehensive clinical, functional and instrumental HRV investigation, electroencephalography (EEG) using 21 monopolar electrodes, and blood pressure (BP) monitoring were embodied in mathematical models that describe the relations of these parameters, multiple regression equations, and generated 3D diagrams. It has been found that a relative increase in the LF range and a decrease in HF one are accompanied by elevations of BP. The EEG α amplitude has been depressed, and α index has decreased. The HRV reduction and modification of the α rhythm structure have been demonstrated to affect the BP values. These data indicate interactions and close relations between the autonomic and central nervous systems and BP.