Clinical Comparison Of Left Ventricular Apex Septal Pacing And Basal Septal Pacing In The Transvenous Crossventricular Septal Approach

Background:Left bundle branch pacing(LBBP)refers to the capture of the left bundle branch trunk or its proximal branches,which has been shown to preserve the physiological synchronization of the left ventricle.However,it is currently difficult to achieve true LBBP.If the implanted electrodes only capture local ventricular myocardium,it will lead to left ventricular septal pacing(LVSP).Studies have demonstrated that LVSP can cause LV systolic asynchrony compared with LBBP,but it has better acute hemodynamic effects than RV apical、RV septal pacing,and biventricular pacing.Both left ventricular basal and apical septal pacing belong to LVSP,but the difference of pacing effect between them is not clear.Previous studies have reported that the left ventricular apical septum is the breakthrough point of the left posterior branch in the left ventricular endocardium.Pacing at this site can quickly activate Purkinje fibers and reverse the left bundle branch to restore the physiological contraction sequence from the apex to the bottom of the heart.The purpose of this study is to compare left ventricular apical septal pacing(LVASP)with left ventricular basal septal pacing(LVBSP)via intravenous transventricular septal pathway,and to provide alternative treatment strategies for patients with LBBP failure.purpose:Randomized LVASP or LVBSP for patients with sick sinus syndrome(SSS)and baseline QRS duration(QRSd)<120ms who failed intraoperative LBBP attempts,and compared short-term pacing parameters between the two Stability,acute electro-mechanical synchrony,and clinical prognosis are aimed at clarifying the feasibility and effectiveness of LVASP and providing alternative treatment strategies for patients with LBBP failure.Method:A total of 40 patients with SSS who were admitted to a hospital from December 2019 to October 2021 and who failed to attempt LBBP and were admitted to a hospital from December 2019 to October 2021 were included in this study.They were randomly divided into two groups.The experimental group received LVASP(20 cases)and the control group received LVBSP(20 cases).The 3830 electrode pacing threshold,perception,impedance and other lead parameters were compared between the LVASP group and the LVBSP group during the operation and at 1 week,3 months,and 6 months after the operation.During follow-up,the pacemaker programmer was used to adjust the AV interval to ensure that the pacemaker was atrial pacing/sensing-3830 electrode pacing,and the cardiac electrical and mechanical synchronization parameters were collected when the 3830 electrode was close to 100% pacing state,and the operation-related parameters were followed up.complications,etc.SPSS26.0 was used for data processing,and P<0.05 was considered statistically significant.Result:1.Comparison between the LVASP groupand the LVBSP group,3830 lead parameters(threshold,perception,impedance)in the operation,1 week after operation,3 months after operation,6 months after operation,etc.There was no significant difference in segment comparison(P>0.05).However,compared with the same group,the impedance of the patients was significantly decreased from 1 week to 6 months after the operation compared with the intraoperative measurement(P<0.05).2.Comparison of cardiac electrical synchronization parameters: There was no significant difference in the preoperative QRSd between the two groups(95.20±14.29 ms VS 95.60±14.38 ms,P>0.05).The QRSd of the LVASP group was wider than that of the LVBSP group at different time periods after the operation,and the difference was statistically significant(P<0.05).Intraoperative measurement of the left ventricle activation time(LVAT)in lead V5 during pacing at the final position of the 3830 electrode was significantly shorter in the LVASP group than in the LVBSP group(56.20±12.31 ms VS71.75±15.16 ms,P<0.05).In the comparison of the frontal plane axis between the two groups after operation,the frontal plane axis in the LVASP group was left deviated,while the electric axis in the LVBSP group was normal,and the difference was statistically significant(P<0.05).3.Comparison of cardiac mechanical synchronization parameters: Compared between the two groups,there was no significant difference in the parameters of preoperative peak strain dispersion(PSD)between the two groups(53.35±7.55 ms VS 53.95±8.97 ms,P=0.820).Compared with the LVBSP group,the PSD of the two groups was shortened,and the difference was statistically significant(P<0.05).4.The LVASP group and the LVBSP group were followed up for 6 months.All patients had no related complications such as lead dislocation,chronic threshold elevation,myocardial perforation,and bag infection,and no related events such as recurrent heart failure hospitalization or death.conclusion:For patients with failed left bundle branch pacing attempts,LV apical septal pacing is superior to LV basal septal pacing in terms of LV mechanical synchronization;LV apical septal pacing has good lead parameters and stable short-term follow-up parameters.No adverse events occurred,it is a safe and feasible pacing method,and it can provide an alternative treatment for patients with LBBP failure.