Charcteristics of the Autonomic Nervous System in Patients with Liver Cirrhosis and its Dependence on the Severity of Portal Hypertension due to the Values of the Heart Rate Variability Parameters

Introduction. Liver cirrhosis, accompanied by the disorders of all organs and systems, including the autonomic nervous system disorders, which greatly accelerates the negative prognosis, taking part in the pathogenesis of the leading syndrome – portal hypertension, is a major cause of death of the hepatological patients. Therefore, the aim of our study was to describe the state of the autonomic nervous system in patients with liver cirrhosis and determine its dependence on the severity of portal hypertension according to the study of heart rate variability indices. Materials and methods. Into the study in randomized manner with the preliminary stratification by the presence of liver cirrhosis were involved 240 patients with varying degrees of portal hypertension severity, who were hospitalized into Gastroenterological Department of Lviv Regional Clinical Hospital. All the patients underwent a comprehensive clinical-laboratory and instrumental examination of all organs and systems, and improved by us, ultrasound doppler-floumetric examination of the abdominal cavity vessels, under which all the patients were stratified into three groups: the first group (PH of the 1st degree) included 122 persons, the second (PH of the 2nd degree) - 57 patients and the 3rd group (PH of the 3rd degree) – 61 patients. Also were examined 40 healthy individuals, which formed the control group. The study of the autonomic nervous system was also performed by our patented method, which provides a comprehensive evaluation of the indices of non-invasive examination of heart rate variability. According to the results of our study, we can observe the dynamics of heart rate parameter, that, due to the heart rate variability indices in patients with liver cirrhosis before and after the physical activity was significantly (p < 0.05) increasing with the increase of the portal hypertension severity, demonstrating the prevailing of the influence of sympathetic over parasympathetic nervous system with the increase of the disease severity. When analyzing the influence of various parts of autonomic influence it was found, that on the basis of reduced total spectral power was observed the imbalance of the autonomic nervous system with the dominance of the sympathetic nervous system in patients of all three groups, especially pronounced in the probe with physical activity. Conclusions. Increasing of the autonomic dysfunction grade, with the transition of the regulation to local (humoral-metabolic) level, according to the heart rate variability parameters study, directly proportional on the severity of portal hypertension in patients with liver cirrhosis, which confirms the role of the autonomic nervous system in the pathogenesis of portal hypertension occurrence and can serve as a reliable diagnostic criterion of portal hypertension detecting and as one of the "markers" to determine the degree of its severity.