Heart Rate Turbulence Indicators in Clinical Practice

Background. Heart disease is the leading cause of death in developed countries. Approximately half of these fatalities are due to sudden cardiac death. Electrocardiogram recording from the body surface allows stratification of patients according to the risk of cardiac arrest without the use of invasive methods. Arrhythmias, particularly ventricular extrasystole, can affect the sinus rhythm pattern. The change in sinus rhythm that occurs after an extrasystole is defined as heart rate turbulence. This phenomenon is not pathological, but some variants are associated with a risk of fatal arrhythmias. Aim. To analyze the indices and clinical significance of cardiac rhythm turbulence according to Holter monitoring in patients with various cardiological abnormalities at the hospital profile department. Material and methods. The study included 54 patients who were routinely treated in a cardiac hospital. Cardiac rhythm turbulence indices were obtained by Holter monitoring. Patients in severe and moderately severe clinical condition were not included in the study. Concomitant and past somatic diseases affecting the state of heart and cardiovascular system were considered. Results and discussion. Deviations in heart rhythm turbulence indices can be detected both in life- threatening arrhythmias and in benign extrasystoles. They are associated with the influence of the autonomic nervous system, but probably have different mechanisms. Deviations of heart rhythm turbulence indices were associated with left ventricular myocardial hypertrophy of concentric remodeling type and with an increased number of low-risk ventricular extrasystoles. To identify patients with arrhythmias of different risk, various threshold values of cardiac rhythm turbulence indices can be used. Conclusion. Factors likely to affect the indices of cardiac rhythm turbulence such as left ventricular myocardial remodeling and hypertrophy were revealed, as well as changes in autonomic nervous system regulatory function, including those associated with the constitutional features of the patient.