OBJECTIVES: Sinus Node Disease (SND) is a common indication for implantation of a permanent pacemaker. In case of subsequent development of atrioventricular block (AVB) it is necessary to upgrade atrial pacemaker (AAI) to dual-chamber (DDD). The aim of the study was to evaluate the influence of atrial fibrillation (AF) history on the risk of AVB development in patients with SND and permanent AAI and its impact on pacing therapy costs. METHODS: Data of 752 patients with SND who had AAI implanted between 1993 and 1997 were identified. The history of AF was established on the basis of preoperative exam. The records of patients were examined to find cases that required further procedure to upgrade AAI to DDD. The cost analysis was performed to assess the strategy of primary DDD implantation in those patients with SND that would receive AAI as a standard. The costs taken into consideration were: pacemaker, leads, implantation procedure, hospitalization. The analysis of sensitivity for main partial costs was performed, future costs were discounted. RESULTS: In the whole group of 752 pts - 144 pts (19.1%) required the upgrade procedure. A total of 417 pts (55.5%) had a history of AF. A total of 105 pts had the subsequent DDD pacemaker implanted in the AF group (25.2%) and 39 in the group with no AF history (11.6%). There were savings of 82€ per patient, in the primary AAI implantation arm, in the whole group and 190€ Euro in the no-AF group whereas both strategies were equal in the group with AF history. CONCLUSIONS: The risk of AVB in SND patients is increased in cases with AF history. The strategy of primary AAI implantation in SND is cost-saving in patients with no history of AF but no such profit is observed in the group with the history of AF.