Impact of pulmonary hypertension of varying severity on the characteristics of the daily variability of the sinus rhythm
Purpose: to search for the parameters of the daily variability of the sinus rhythm (VSR) and VSR corresponding to different ranges of heart rate changes, which are most strongly affected by pulmonary hypertension of various etiologies and severity. Material and methods. The study included 67 patients (18 men and 49 women aged 18 to 59 years) with two types of pulmonary hypertension: 42 patients (6 men and 36 women) with idiopathic pulmonary hypertension (IPH) and 25 patients (12 men and 13 women) with chronic thromboembolic pulmonary hypertension (CTPH). Some patients examined two or more times at different hospitalizations. As a result, 224 examinations conducted in combination with Holter ECG monitoring and subsequent analysis of the daily VSR. As a control group, the results of XM ECG of 67 healthy individuals (29 women and 38 men aged 18 to 55 years) were used. The daily HRV evaluated in age-comparable subgroups of control groups and PH: 18-29 years, 30-39 years, 40-49 years and 50-59 years. HRV parameters were determined using a modification of the VSRA-SSR method, taking into account the presence of double fractures (DFR) on the rhythmogram. Results. 1) The appearance of IPH, CTPH and the increase in PH FC have approximately the same effect on the parameters characterizing the daily HRV as a whole, and on the HRV parameters corresponding to different ranges of heart rate changes. 2) The effect of PH on HRV clearly depends on the age of the patient and the severity of the disease characterized by PH FC. At the age of 40, both the appearance of PH and the increase in PH FC generates a tendency to decrease HRV, regardless of the presence or absence of DIR. At the age of over 40 years, this trend begins to weaken, and at the age of 50-59 years, in areas with DIR, it changes to a tendency to increase HRV with increasing severity of the disease. 3) The most obvious effect of PH on HRV is manifested in the form of a decrease in HRV in the areas of the rhythmogram without DIR. This applies both during the whole day and in all ranges of heart rate changes studied by us. 4) The effect of PH on HRV is most expressed in the heart rate ranges > 75 beats/min. 5) The data obtained can be useful to analyze the relationship between the dynamics of the daily HRV with the dynamics of the parameters of the functional state of the patient with PH, obtained according to his clinical and instrumental examination.