Evaluation of heart rate variability in patients with different forms of pulmonary hypertension

Pulmonary hypertension (PH) is a severe pathology of the cardiovascular system with extremely poor prognosis, if unreated. Early diagnosis of PH is difficult, due to the absence pathognomonic symptoms, and at the initial stage the disease may be asymptomatic. An increase in pulmonary vascular resistance and pressure in the pulmonary artery cause severe dysfunction of the right ventricle, which affects the functional status of patients. The assessment of heart rate variability (HRV) parameters is used to predict the increased risk of sudden death in various diseases of the cardiovascular system and the functional status of the body. HRV is mainly regulated by the sympathetic and parasympathetic divisions of the autonomic nervous system. It is noted that pulmonary arterial hypertension is associated with increasing of sympathetic activity. The review, based on the analysis of the pathophysiological mechanisms of pulmonary arterial hypertension and chronic thromboembolic PH, presents the results of studies assessing the time and spectral parameters of HRV in patients with PH of various etiologies.