This work is devoted to the dynamic study of heart rate variability indicators for one year in patients with paroxysmal atrial fibrillation treated with antiarrhythmic drugs metoprolol and cordarone. The study found that patients treated with metoprolol monotherapy had a weakening of parasympathetic effects on the heart, due to a decrease in Mean by 12.9%, Mo by 13%, Amo by 29.4%, SDNN by 28.3% compared to the group of healthy individuals, but they differed in stable indicators of heart rate variability and 33% retained sinus rhythm during the year. With cordarone monotherapy, there was a curative effect of sympathetic and parasympathetic effects on the heart, as indicated by an increase in: Mean by 15.9%, Mo by 15.9%, IVR by 95.5%, Amo by 41.1% and a decrease in SDNN by 37.5%, compared with the group of healthy individuals at the initial stage. A year later, a negative dynamics was revealed - the predominance of sympathetic influences on the heart compared to the groups of healthy individuals and the control due to an increase in: IVR by 363.3% and 238.5%; VPR by 116.7% and 106%; Amo by 111.2% and 72.9; IN by 304% and 246.8%; PAPR by 92% and 79.1%, respectively. During the year, 39% of patients left the study due to the replacement of antiarrhythmic therapy and 16.5% due to the development of a permanent form of atrial fibrillation. In the remaining patients in the study, in comparison with their initial data, there was a predominance of sympathetic effects on the heart due to an increase in IVR by 137%. In combination therapy with metoprolol and cordarone, there were no significant changes in heart rate variability compared to the initial ones. Initially, there was a decrease in overall heart rate variability due to a decrease in SDNN by 28.4% and a decrease in parasympathetic effects on the heart due to an increase in Amo by 45.2% and a decrease in Delta X by 32.9% compared to the group of healthy individuals. After a year, 40% left the study due to the replacement of antiarrhythmic therapy and 30% due to the development of a permanent form of atrial fibrillation. During dynamic observation of patients, it was found that the following indicators have the most important prognostic value in the development of atrial fibrillation: SDNN, Delta X and RMSSD. Therefore, it is very important to register an ECG with the measurement of these indicators at least once every 3 months for timely correction of treatment.
