Comparison Of Effects On Patients With Cardiac Function Between RVA Pacing And RVOT Pacing With The Same(DDD) Pacemaker Model

Objective:To compare the effcts of right ventricular outflow tract septum (RVOT) pacing and right ventricular apex (RVA) pacing on left ventricular remodeling and cardiac function.Methods:Patients with SSS/AVB who were implanted with DDD pacemakers from January2009to December2012were enrolled.Depending on the ventricular electrode implanted part is divided into group A (RVA pacing) and group B (RVOT pacing). Each group according to preoperative patients with left ventricular ejection fraction (LVEF) were divided into two subgroups.12months of follow-up data to be obtained,analysis of two groups of postoperative patients with LVEF, LAD, LVEDD and various post-operation parameters, Paced QRS duration and postoperative complications.Results:All219cases of surgeries were successful, the two group showed no significant difference in surgical success rate or postoperative complications.After12months of follow-up, Pacing threshold、electrode impedance of group A significantly decreased(P<0.05), R wave amplitude showed no significant changes(P>0.05); Electrode impedance of group B significantly decreased (P<0.05), but pacing threshold-. R wave amplitude showed no significant changes(.P>0.05).QRS duration in Group B significantly reduced than it in group A(145.09±4.96ms vs157.40±12.44ms, P<0.01). compared with preoperative, Group A reduced LVEF, increased LAD and LVEDD, the differences were statistically significant (P<0.05); LVEF, but in group B, Significant changes Not been found (P>0.05). Preoperative LVEF≥50%of the patients:LVEDD in both group increased compared with that before surgery (P<0.05), differences of LVEF and LAD has no statistical significance (P>0.05). Preoperative LVEF<50%of the patients:Group A reduced LVEF、LAD, increased LVEDD, differences were statistically significant (P<0.05), Group B has no such significant differences(P>0.05).Conclusion:RVOT pacing is safe and feasible in clinical application. For patients with cardiac insufficiency, RVOT pacing can make ventricular systolic synchronization, reduce the damage to the heart function. For patients with normal cardiac function, although the RVOT pacing provides more synchronous ventricular contraction, in the aspect of preventing cardiac remodeling and preserving LV systolic function has not yet found any better than RVA pacing after12months of pacing.