The effects of VVI and AAI pacing modes on paroxysmal atrial tachyarrhythmias of sick sinus syndrome

bjective To compare the longterm effects of VVI and AAI pacing on paroxysmal atrial tachyarrhythmias of sick sinus syndrome(SSS). Methods A longterm followup survey was carried out in 41 cases of VVI pacing and 38 cases of AAI pacing by clinical examinations,electrocardiography(ECG) and dynamic ECG.The mean followup time was 3926 and 2418 months ,respectively. Results Among the VVI pacing group,21 cases developed sustained atrial fibrillation,in the other 20 cases the frequency and duration of episodes of paroxysmal atrial tachyarrhythmias were increased markedly than that before implantation(P005)and evidence of systemic embolism was found in 6 patients.No death and lead dislocation occurred in this group.Among AAI pacing group,the paroxysmal atrial tachyarrhythmias were satisfactorily controlled in 19 cases,the frequency and duration of the atrial tachytachyarrhythmia episodes were decreased markedly than that before implantation(P005)in the other 19 cases and no sustained atrial fibrillation,systemic embolism and death were found.Lead dislocation in 1(3%)patient,and first degree AV block in 1(3%)patient occurred in this group.The life quality of all patients in AAI group was improved significantly after pacemaker implantation. Conclusion AAI is a reliable and safe pacing mode which can inhibit paroxysmal atrial tachyarrhythmias of SSS and is apparently superior to VVI pacing.