VARIABILITY OF THE HEART RHYTHM AS AN ADDITIONAL MARKER FOR DETERMINING VEGETATIVE FUNCTIONS IN PATIENTS WITH CHRONIC CEREBRAL ISCHEMIA
Aim. Practical cardiology is in constant search for non-invasive vascular risk markers. Heart rhythm reflects the body's response to various stimuli of the external and internal environment. Heart rate variability (HRV) has a prognostic and diagnostic value and allows timely identification of conditions that threaten life. The results of an instrumental examination of heart rhythm fluctuations in patients suffering from chronic cerebral ischemia against the background of angina pectoris of different functional classes allows to evaluate the prognosis of the disease and select the appropriate treatment. Materials and methods. An assessment of the state of the mechanisms of regulation of physiological functions in patients suffering from chronic cerebral ischemia against the background of angina pectoris of different functional classes was obtained according to spectral and temporal analysis of heart rate variability using electrocardiographic monitoring. The spectral characteristics of the heart rate variability were studied: HF (high frequency), LF (low frequency), VLF (very low frequency). Results. Heart rhythm regulation in patients with chronic cerebral ischemia occurred under the influence of neurohumoral mechanisms. The imbalance of functional systems was caused by changes in the autonomic nervous system, which disrupted the normal functioning of the sympathetic and parasympathetic parts. We marked decrease in the activity of the parasympathetic autonomic nervous system, which changed the indices of spectral analysis, while the high-frequency component of the spectrum was characterized by a decrease, while the low-frequency component was characterized by an increase. The progression of stable angina of tension (SAT) in patients with chronic cerebral ischemia (CCI) occurred with disruption of the autonomic nervous system (ANS) and was associated with a shift in the physiological response towards sympathetic activity. This was particularly pronounced in patients in group 2 with CCI on the background of SAT III FC, as the regulatory mechanisms were in a critical state of tension against the background of long-term chronic ischemia, they showed a high level of humoral modulation of regulatory mechanisms, which was manifested by excessive VLF and high-frequency oscillations. Conclusions. A connection was established between the autonomic nervous system and chronic cerebral ischemia, which was expressed in the imbalance of the ANS, associated with reliable signs of the dominant sympathetic system, which was associated with the progression of stable angina of tension.