Influence of Different Atrial Pacing Ratios on Left Heart Function and Occurrence of Paroxysmal Atrial Fibrillation in Patients with Sick Sinus Syndrome

LIU Wenxiu; LIU Liangbing; GUI Chenli; CHENG Fengqin; HU Bo

doi:10.3639/j.issn.2095-3097.2025.05.006

Abstract：Objective To observe the influence of different atrial pacing ratios during dual-chamber pacemaker im-plantation on left heart function and the occurrence of paroxysmal atrial fibrillation in patients with sick sinus syndrome(SSS).Methods From January 2023 to December 2024,120 patients who were diagnosed as having SSS with normal atrioventric-ular conduction function and implanted with a dual-chamber pacemaker(DDDR/DDD)in Mianyang 404 Hospital were en-rolled as study subjects.According to the atrial pacing ratios of patients,they were divided into a high atrial pacing group(HAP group,RA pacing ratio≥50%,68 cases were enrolled;3 cases withdrew,and 65 cases were finally included for analysis)and a low atrial pacing group(LAP group,RA pacing ratio<50%,52 cases were enrolled,and there were no withdrawals).Compare left ventricular function and incidence of paroxysmal atrial fibrillation at 1 and 3 months postoperatively between two groups.Results In the HAP group,the absolute values of left atrial reservoir strain during reservoir phase(LASr),left atrial reservoir strain during conduit phase(LAScd)and left atrial reservoir strain during contraction phase(LASct)at 3 months post-surgery were decreased compared with those at 1 month post-surgery(P<0.05).Compared with those at 1 month,the absolute values of LASr and LAScd in the LAP group were also reduced at 3 months post-surgery(P<0.05).At 3 months,the absolute values of LASr,LAScd and LASct in the LAP group were higher than those in the HAP group(P<0.05).The absolute value of left ven-tricle global longitudinal strain(LVGLS)in the HAP group was lower at 3 months post-surgery than at 1 month post-surgery(P<0.05).The absolute value of LVGLS at 3 months post-surgery was higher in the LAP group than in the HAP group(P<0.05).The short-form 36-item health survey score in the two groups at 1 month and 3 months post-surgery was higher than that at 1 week post-surgery(P<0.05).At 3 months post-surgery,paroxysmal atrial fibrillation occurred less frequently in the LAP group compared to the HAP group[9.62%(5/52)vs 33.85%(22/65),P<0.05].Conclusion Compared with high atrial pacing,low atrial pacing results in relatively small changes in left atrial and left ventricular myocardial strains in SSS patients with normal atrioventricular conduction function,and it can better reduce the risk of occurrence of paroxysmal atrial fibrillation.A low atrial pacing management strategy may have long-term clinical benefits for patients.