Comparative Study On The Influence Of Low Atrial Septal Pacing And Right Atrial Appendage Pacing On New Onset Atrial Fibrillation In Patients With Sick Sinus Syndrome And Interatrial Block

BACKGROUND Sick sinus syndrome（SSS）is a clinical syndrome caused by pathological changes of sinoatrial node and its surrounding tissues,which leads to a variety of arrhythmias.SSS with symptoms is an indication for pacemaker implantation.The traditional implantation site of atrial electrode is right atrial appendage,which has the advantages of convenient operation,stable pacing,not easy to dislocation and so on.However,the study found that right atrial appendage pacing is not consistent with the physiological pacing sequence,and will increase the incidence of atrial fibrillation（AF）.With the gradual promotion of low atrial septal pacing,it has been found that low atrial septal pacing can improve the synchronization of left and right atrium,but whether it can reduce the incidence of AF is still controversial.The analysis suggests that it may be related to whether interatrial block（IAB）is complicated before pacing.Therefore,this study compared the influence of low atrial septal pacing and right atrial appendage pacing on new onset AF in patients with SSS and IAB,and to explore the beneficiaries of low atrial septal pacing.METHODS Fifty-eight patients with SSS and IAB hospitalized in Maanshan people’s Hospital from January 2019 to June 2020 were divided into low atrial septal pacing group（LAS）and right atrial appendage pacing group（RAA）according to the implantation site of atrial electrodes.The operation time,radiation exposure time and dose were compared between the two groups.The changes of P wave duration and P wave dispersion（Pd）on the ECG before and after operation,the changes of electrode parameters during operation and 1,3,6 and 12 months after operation,related complications and the occurrence of new onset AF were observed.RESULTS（1）During the follow-up period,there was no significant difference in pacing parameters（pacing threshold,P wave perception,electrode impedance）and pacing related complications between the two groups（P（29）0.05）.（2）The operation time（71.0±5.9min vs.50.5±4.6min,P（27）0.05）,X-ray exposure time（7.2±2.0min vs.4.7±1.1min,P（27）0.05）and radiation dose（51.3±12.4m Gy vs.45.6±6.3m Gy,P（27）0.05）in LAS group were higher than those in RAA group,and the difference was statistically significant.（3）P wave duration（117.7±7.0ms vs.135.1±8.9ms,P（27）0.05）and Pd（23.9±4.5ms vs.31.5±5.5ms,P（27）0.05）in LAS group were significantly lower than those in RAA group after pacing,while P wave duration（117.7±7.0ms vs.128.8±6.9ms,P（27）0.05）and Pd（23.9±4.5ms vs.28.1±5.4ms,P（27）0.05）in LAS group were significantly shorter than those before pacing.（4）There were 7 patients（12.1%）with new onset AF after pacing.There were 0 cases in LAS group and 7 cases in RAA group.There was significant difference（0.0% vs.20.0%,P=0.035）between the two groups.CONCLUSION Low atrial septal pacing is safe and feasible.For patients with SSS and IAB,it can reduce the incidence of postoperative new AF,but the implantation method is relatively complex.