Features of Heart Rate Variability in Patients with Coronary Heart Disease and Risk Factors for Cardiovascular Disease According to the SCORE Charts in the Presence of Heart Rate Turbulence
Authors: Vytryhovskyy A. I. 
Published: September 2016

The objective of the research was to develop new approaches to the prediction, prevention and treatment of complications in patients at high and very high total cardiovascular risk based on the assessment of heart rate turbulence.Materials and methods. 319 patients were examined to study the role of heart rate turbulence in the formation and progression of sudden cardiac death in the cardiovascular continuum based on the Holter monitoring. All patients were divided into 4 groups: Group 1 included patients with coronary heart disease without concomitant risk factors such as smoking, obesity, metabolic syndrome; Group 2 consisted of patients smoking tobacco for more than 2 years (those at very high cardiovascular risk); Group 3 included patients with metabolic syndrome without existing coronary heart disease or arterial hypertension (those at high cardiovascular risk); Group 4 consisted of 50 patients with metabolic syndrome and arterial hypertension (the control group).Results. In practically healthy people with the phenomenon of heart rate turbulence, there was a high level of sympathetic activity of the autonomic nervous system, which was more pronounced in the passive period of the day. In people with postinfarction cardiosclerosis and the phenomenon of heart rate turbulence hypersympathicotonia being associated with high psycho-emotional stress was typical in the active as well as the passive period of the day; the central mechanisms of regulation prevailed over autonomous ones. In people with coronary heart disease (postinfarction cardiosclerosis) psycho-emotional stress and functional state of the cerebral cortex played an important role in the pathogenesis of the disease. In the passive period of the day, the tension value of the total body regulation decreased, mainly due to high-frequency component of heart rate variability. Hypersympathicotonia and high activity of the vasomotor center at night explain the high incidence of complications and exacerbations of coronary artery disease in the passive period of the day.  In individuals at very high cardiovascular risk according to the SCORE charts with the phenomenon of heart rate turbulence the QT interval lengthening was not observed. The feature of this group was the moderate total tension of heart rate variability in the active period of the day and its rise to the highest limits during the passive period of the day, which was associated with low activity of all spectra. The stress index in patients at very high cardiovascular risk according to the SCORE charts in the passive period of the day reduced compared to the active period of the day. The indices of acceleration and deceleration of the sinus rhythm in patients at very high cardiovascular risk according to the SCORE charts were within normal limits. In individuals at high cardiovascular risk according to the SCORE charts with the phenomenon of heart rhythm turbulence the parameters of heart rate turbulence acceleration were below normal limits; the paramters of deceleration were normal; shortening of the QT interval was not observed.Conclusions. The determination of heart rate turbulence is quite simple, non-invasive, affordable screening method of forecasting the occurrence and development of cardiovascular diseases as well as early detection of patients predisposed to sudden cardiac death in the general population.