Abstract: Objective To investigate the influence and clinical significance of single and dual- chamber pacing on central aortic pressure (CAP) and augmentation index (AI) in non-smoking individuals. Methods Totally, 83 non-smokers with pacemaker-implanted were consecutively enrolled in this study, and they were divided into three groups: dual-chamber pacemaker group (DDD, n=35), single-chamber pacemaker group (VVI, n=33) and control group (n=15). Heart rate (HR), CAP, AI, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured in three groups of patients. Finally, DDD pacing mode was turned into VVI pacing mode in patients of DDD group and the indexes were measured again. All of the indexes were recorded and analyzed. Results There were no significant changes in baseline characteristics and laboratory data between three groups (P＞ 0.05). Left atrial diameters were significantly higher in VVI group than those of control group (P＜ 0.05). Values of CAP were significantly higher in DDD group than those of control group and VVI group (P＜ 0.05). Values of AI, corrected AI (AIc) and brachial BP were significantly higher in DDD group than those of VVI group (P＜ 0.05). Values of CAP and brachial BP were significantly lower in VVI group than those of control group (P＜ 0.05), while no significant changes were found in AI and AIC between VVI group and control group (P＞ 0.05). All of these indexes (CAP, AI and brachial BP) were significantly reduced after the pacing mode was changed (P＜ 0.05). Conclusion In nonsmokers, dual-chamber pacing mode can increase CAP and AI.

Key words: arrhythmias, cardiac, cardiac pacing, artificial, single-chamber pacing, dual-chamber pacing, central aortic pressure, augmentation index