Abstract. The article presents the results of the effectiveness of preventive antiarrhythmic monotherapy with sotahexal and cordarone based on heart rate variability and examination of patients at intervals of every 3 months for one year. The relevance of studying heart rate variability indicators is beyond doubt. The simplicity and non-invasiveness of this procedure dictates its increasing use. As a result of the study, the mechanism of occurrence of paroxysms of atrial fibrillation was shown both in patients with the existing paroxysmal form of atrial fibrillation, and in comparison, groups, where the debuts of this disease were recorded as a result of the study. It is known that with age there is an increase in diseases of the cardiovascular system, including atrial fibrillation. Elderly patients make up the bulk. Therefore, properly selected antiarrhythmic therapy based on heart rate variability indicators can help reduce morbidity in this group of patients. When studying the effectiveness of antiarrhythmic therapy on the example of representatives of the III class of antiarrhythmic drugs sotahexal and cordarone, it was found that the effectiveness of monotherapy with sotahexal and cordarone by the end of 1 year of the study was 74 and 71%, respectively. Indicators of heart rate variability in patients receiving sotahexal after 1 year did not significantly differ from each other, and at the initial stage of treatment, indicators characterizing the tone of the parasympathetic nervous system prevailed over the same indicators of patients receiving cordarone, over the tone differed from the initial ones in the downward direction. In patients receiving cordarone, a year later, there was a shift in the vegetative balance towards sympathicotonia compared with baseline indicators.

Abstract. The study shows the values of heart rate variability in patients with paroxysmal atrial fibrillation treated with allapinin monotherapy and a combination of allapinin with metoprolol, allapinin with sotahexal and allapinin with diltiazem with preventive antiarrhythmic therapy. Analysis of heart rate variability allows you to determine the state of the autonomic nervous system. A high probability of an unfavorable outcome of diseases of the cardiovascular system is observed with the predominance of the tone of the sympathetic nervous system and a decrease in the tone of the parasympathetic nervous system. A decrease in heart rate variability and a predominance of sympathetic nervous system tone are predictors of the occurrence of another paroxysm in patients with paroxysmal atrial fibrillation. Indicators of heart rate variability are of great importance in the selection of antiarrhythmic therapy. The initial predominance of the tone of the parasympathetic nervous system in comparison with healthy ones and the absence of negative dynamics after 1 year was recorded in patients with paroxysmal atrial fibrillation with allapinin monotherapy. Patients treated with a combination of allapinin and metoprolol had a predominance of the tone of the parasympathetic nervous system initially compared with the healthy group and a transition to sympathicotonia after 1 year compared with healthy, control and their own baseline values. Patients receiving allapinin and sotahexal had no significant differences either at the beginning of the study or after 1 year. Predominance of sympathetic nervous system tone was registered in patients treated with allapinin and diltiazem by the end of 1 year of the study in comparison with a group of healthy.