The monitoring tactics in patients with paroxysmal atrial fibrillation (AF) and an implanted pacemaker needs to be clarified, especially in the early stages after device implantation. Objective. Antiarrhythmic therapy control and pacemaker work optimization in patients with paroxysmal AF in the first 6 months after device implantation. Materials and methods. The study included 103 patients – 39 (37.9%) men and 64 (62.1%) women; the average age was 76.4 8.9 years. All patients underwent echocardiography before surgery. After 3 and 6 months a follow-up examination, which included a pacemaker check, 12-lead electrocardiography, a sixminute walk test and, if necessary, 24-hour monitoring of the electrocardiogram was performed. The results were processed using the Statistica 10.0 software; χ2, Fisher's tests and Mann-Whitney U-test were calculated. Differences were considered significant if p <0.05. Results. The antiarrhythmic therapy control, based on the information from the memory of the pacemaker was more effective than other methods. It turned out that 68% of arrhythmias and all indications for pacemaker work correction were registered within the first month after implantation, during the first pacemaker check. During the second check the number of patients require correction of the pacemaker function significantly decreased (p<0.05), while the need for antiarrhythmic therapy correction remained the same. Frequent right ventricular stimulation was detected in 45 patients, and was corrected in 31 (69%) patients. At the first check, a six-minute walk test revealed chronotropic incompetence in 32% patients with baseline sick sinus syndrome. The progression of heart failure in patients with left ventricular ejection fraction less than 40% with frequent right ventricular pacing was observed only in 50% of cases. Heart failure more often progressed in patients with left ventricular hypertrophy and diastolic dysfunction and right ventricular dilatation (p=0.04). Conclusion. Regular pacemaker check can significantly improve the control of antiarrhythmic therapy and promptly identify frequent right ventricular pacing. The first check of the pacemaker should be done 1 month after implantation, the second – 3 months after the first check. For patients with an initial sick sinus syndrome, the first examination should be accompanied with a six-minute walk test.