Characteristics and Theoretical Foundations of Methods to Analyze Heart Rate Variability

The present stage of the society development is characterized by significant achievements in the development of methods to study the microstructure of a living organism and rapid development and availability of the advanced information technologies. One of the spheres of applying computer technologies is the assessment of biological rates, and in particular, heart rate variability. The aim of the paper is to analyze and generalize the literature sources in terms of the methods of heart rate variability. Results. The scientific publications on the historical development of the methods for analyzing heart rate variability, the characteristics of statistic, geometric and spectral methods of haemodynamic indicator oscillations were analyzed. The data concerning the requirements to the duration of registration of cardiointervalograms and the reproducibility of their characteristics were considered. It was found out that significant number of investigations concerning the variability of heart rate in humans and animals had been conducted. However, there are no unified norms of spectral component values of these indicators that may be associated with many factors: the heterogeneity of the studied samples, the application of the different methods of spectral analysis, non-compliance with the standard conditions for measurements. At the same time, almost no attention is paid to the analysis of inter-individual deviance of wave structure indicators of heart rate and their reactivity to the load. It can lead to the false evaluation of measurement results. Few publications focus on the study of the oscillations of blood stroke volume in healthy individuals and cross-spectral analysis of this indicator with the changes of R-R interval duration. Therefore, literature analysis shows the necessity of further investigation of both methodological and theoretical aspects of heart rate variability, their individual features in healthy individuals. Conclusions. There are opportunities for the improvement of existing methods and the development of new ones of analysis and interpretation of heart rate variability. Prospects for further investigations. So, analysis of literature determines the necessity for further investigations of variability of heart rate and also individual peculiarities in healthy people.