Systemic rearrangement of the heart rhythm in the process of organism aging. Spectral analysis

Changes in the cardiovascular system are systemic during ageing. The aim of this work is to describe systemic regularities of changes in heart rate variability (HRV) parameters during ageing in healthy subjects. HRV of 73 healthy subjects aged 11–76 years from the PhysioNet database were used, divided into 3 groups: young 11–17 years, middle-aged 24–55 years and elderly 56–76 years. Using the Hilbert-Huang method and wavelet analysis, spectral curves of empirical HRV modes were obtained, for which maxima and their corresponding frequencies were determined. Nine modes were identified. A 2-fold decrease in autonomic control modes and, to a lesser extent, very low frequency modes (0.002–0.04 Hz) was found in the elderly compared to the young. Very low frequency HRV oscillations (