Researched the structure of Very Low Frequency (VLF) spectrum of heart rate variability (HRV) and its nonlinear behavior in a relationship with the energy of oscillations, baroreflex and parasympathetic activity at functional tests of low intensity in 100 subjects (seven-test, deep breathing), including active orthostatic test of 32 subjects with orthostatic tachycardia in comparison to the control group of 20 subjects. There were three stages of research. The first stage: created the method of spectral analysis of separate components of VLF.
