Synchronization of the Processes of Autonomic Control of Blood Circulation in Humans Is Different in the Awake State and in Sleep Stages

Abstract

The influence of higher nervous activity on the processes of autonomic control of the cardiovascular system and baroreflex regulation is of considerable interest, both for understanding the fundamental laws of the functioning of the human body and for developing methods for diagnostics and treatment of pathologies. The complexity of the analyzed systems limits the possibilities of research in this area and requires the development of new tools. Earlier we propose a method for studying the collective dynamics of the processes of autonomic control of blood circulation in the awake state and in different stages of sleep. The method is based on estimating a quantitative measure representing the total percentage of phase synchronization between the low-frequency oscillations in heart rate and blood pressure. Analysis of electrocardiogram and invasive blood pressure signals in apnea patients in the awake state and in different sleep stages showed a high sensitivity of the proposed measure. It is shown that in slow-wave sleep the degree of synchronization of the studied rhythms is higher than in the awake state and lower than in sleep with rapid eye movement. The results reflect the modulation of the processes of autonomic control of blood circulation by higher nervous activity and can be used for the quantitative assessment of this modulation.

Method of Extracting the Instantaneous Phases and Frequencies of Respiration from the Signal of a Photoplethysmogram

“…However, the interaction between respiration and the low-frequency component of a heart rhythm, which is associated with the process of autonomic control of blood circulation, also plays an important role in the cardiorespiratory interaction. It has been shown that this type of cardiorespiratory interaction is important in studies of sleep [10][11][12] and healthy aging [13][14][15][16], in the assessment of psychophysiological state [17], in the prediction of complications of cardiovascular diseases [18,19], and in basic research [20,21].…”

Changes in the Power and Coupling of Infra-Slow Oscillations in the Signals of EEG Leads during Stress-Inducing Cognitive Tasks

“…Analysis of the strength and structure of couplings between such processes is a useful tool for constructing quantitative indices that characterize changing physical and psychophysiological states [4][5][6][7]. Methods for detecting the interaction of various body systems have been successfully applied to the estimation of the biological age [8,9], classification of sleep stages [10][11][12], diagnosis of the severity of diseases of the cardiovascular system [13][14][15], and stress diagnosis [5,7,16]. The latter is important for the implementation of continuous monitoring of the stress level in everyday life and the identification of people at risk of developing stress-related disorders.…”

“…Generally, the study of brain activity during changes in the psycho-emotional state is carried out in the following frequency ranges: delta (0.5-4 Hz), theta (4-8 Hz), alpha (8)(9)(10)(11)(12)(13), beta (14-30 Hz), and gamma . At the same time, the analysis of infra-slow oscillations of brain potentials with a frequency of less than 0.5 Hz can provide important additional information for diagnosing the development of stress.…”

“…The infra-slow oscillations in EEG signals were analyzed in the studies [16,[37][38][39], which dealt with cognitive task-solving. The infra-slow oscillations of brain potentials correlate with human behavior [40] and change during sleep [10][11][12][41][42][43].…”