Systemic Rearrangement of the Heart Rhythm in the Process of Organism Aging: Spectral Analysis

Changes in the cardiovascular system are systemic during aging. The aim of this work is to describe systemic patterns of changes in heart rate variability (HRV) parameters during aging in healthy subjects. HRV data of 73 healthy subjects aged 11-76 years from the PhysioNet database were used, which were divided into three groups: young (11-17 years old), middle-aged (24-55 years old), and elderly (56-76 years old). Using the Hilbert-Huang method and wavelet analysis, spectral curves of empirical HRV modes were obtained, for which the maxima and their corresponding frequencies were determined. Nine modes were identified. A twofold decrease in the autonomic control modes and, to a lesser extent, in the very-low-frequency modes (0.002-0.04 Hz) was found in the elderly compared to the young. Very-low-frequency HRV oscillations (<0.001 Hz) did not change with age. The results obtained may serve as a basis for physiological interpretation of HRV regulation processes and may be useful in the development of controlled anti-aging therapy.