Different Influences Of Single And Dual-chamber Pacing On Hemodynamics, Central Aortic Pressure And Peripheral Arteriosclerotic Indices

Objective: To assess the different effect of single-chamber pacing on cardiac output (CO), central aortic blood pressure (CAP), brachial blood pressure, and peripheral arteriosclerosis compared with dual-chamber pacing, and investigate the probable mechanism.Methods:103patients with pacemaker-implanted were sequential enrolled in this study. The patients were divided into three groups:single-chamber pacemaker group (41cases), dual-chamber pacemaker group (42cases) and control group whose pacemakers were not working (20cases) when the patients were examined. The cardiac output(CO),cardiac index(CI), brachial systolic blood pressure(SBP),brachial diastolic blood pressure (DBP),mean arterial pressure(MAP),central aortic pressure(CAP), augmentation index(AI), pulse wave velocity(PWV),ankle-brachial index(ABI) were measured in all enrolled subjects. And then we turned DDD pacing mode of patients in dual-chamber pacemaker group into VVI pacing mode, and measured these targets again.Results:①Among the three groups, the control group, DDD group and VVI group, both of the value of PWV and ABI had no significant difference (p>0.05).There was also no significant difference before and after turning the DDD pacing mode into VVI pacing mode(p>0.05).②The value of CO in DDD group(4.21±0.87L/min)was significantly higher than the value of CO in VVI group(3.42±0.83L/min)(p<0.05). The value of CO in DDD group and VVI group showed a significant decrease compared with the control group. The value of CO decreased from4.26±1.12L/min to3.61±1.18L/min after turning pacing mode (p<0.05).③The value of CI in the control group was2.69±0.47L/min.m2and significantly higher than the value of CI in DDD group(2.37±0.44L/min.m2) and VVI group(2.15±0.59L/min.m2)(p<0.05). There was no significant difference between the DDD and VVI group (p>0.05). There was also no significant difference before and after turning the pacing mode (p>0.05).④The values of SBP, DBP and MAP in control group were 129.6±19.07mmHg,69.9±11.93mmHg,90.15±13.64mmHg respectively; Those in DDD group were136.4±20.09mmHg,70.9±8.44mmHg,93.83±11.97mmHg respectively; Those in VVI group were120.73±8.19mmHg,64.62±11.52mmHg,84.54±12.70mmHg respectively. The values in DDD group were significantly higher than VVI group (p<0.05). There was no significant difference between the control group and DDD group, as same as control group and VVI group(p>0.05).The values of SBP,DBP and MAP showed a significant decrease after turning the DDD pacing mode to VVI pacing mode (p<0.05).⑤The value of CAP in DDD group was149.67±19.62mmHg and was significantly higher than the control group (138.70±18.69mmHg) and VVI group(124.33±19.34mmHg)(p<0.05). The value of CAP in control group were significantly higher than VVI group (p<0.05). The value of CAP after turning the pacing mode (116.11±25.17mmHg) showed a significant decrease compared with before doing that (136.26±22.21mmHg)(p<0.05).⑥The values of AI and AIc in control group were78.95±13.31and78.50±11.52respectively. Those in DDD group were88.19±10.29and85.10±9.19respectively. Those in VVI group were81.26±12.28and77.13±12.13respectively. The values in DDD group were significantly higher than control and VVI group (p<0.05). There was no significant difference between the control group and VVI group (p>0.05).The values of AI and AIc after turning pacing mode (77.26±18.42and73.87±17.72) showed a significant decrease compared with before doing that (83.58±12.86and79.84±11.90)(p<0.05).Conclusion:①There is no evident function on patients’ peripheral arteriosclerotic indices after implanting pacemaker whether single-chamber or dual-chamber pacemaker.②Dual-chamber pacing could significantly enhance patients’CO and CI compared with single-chamber pacing. But both of them could significantly enhance systemic resistance and reduce people’s cardiac function.③Dual-chamber pacing could significantly enhance patients’ brachial SBP and DBP, which could make a positive role in keeping people’s henodynamics stable. ④Dual-chamber pacing may boost people’s CAP and AI, which could make a negative role in people’s cardiovascular events and long-term prognosis.