Compare Right Ventricular Inflow Tract Posterior Septal Endocardium To Right Ventricular Apex

Objective To explore the clinical feasibility of right ventricular inflow tract posterior septal endocardium pacing ,in order to find another pacing site for tined electrode. Method 34 patients received permanent dual-chamber pacemaker ,who cardiac function belong to NYHA Ⅰ.All patients were subdivided into two groups :right ventricular inflow tract posterior septal endocardium (18,male 10 female 8 mean-age 63.39±11.11years);right ventricular apex (RVA16,male 8 female 8 mean-age 65.94±11.22years).Under fluoroscopic guidance ,the ventricular lead was positioned the RVA and right ventricular inflow tract posterior septal endocardium.Different from the RVA,the location standard of right ventricular inflow tract posterior septal endocardium is that the lead tip do not surpass the spinal left at posteroanterior.Compare pacing thresholds,pacing electrocardiogram and the influence of cardiac function between two sites. Results There was no difference in pacing thresholds,R wave amplitude and endocardium pacing impedance between two pacing sites at the time of implantation .After 3 months follow-up,there was no lead dislocation,no difference in pacing thresholds.Self-compared the pacing electrocardigram of 18 patients,we found the meam QRS duration was significantly shorter during right ventricular inflow tract endocardium pacing than during RVA(0.188±0.003ms vs 0.199±0.003ms P<0.05). TheV2R V3R V4R V5R V4S wave amplitude was significantly higher during right ventricular inflow tract endocardium pacing than during RVA pacing P<0.01.There was no significance in V1R V1S V2S V3S V5S .Under the self-heartrate and completely pacing rate ,compare the cardiac function( ESV EDV EF% SV) between two sites before implatation and 3 months follow-up.there is no significance .In right ventricular inflow tract endocardium pacing group, compare the ESV EDV EF% SV.we found the ESV increased slightly and EDV EF% SV decreased after implantation .But there was no significance. Conclusion In using tined electrod ,pacing at right ventricular inflow tract posterior septal endocardium was an optimal pacing site.