The Influence Of Right Ventricular Septal Pacing On Cardiac Function And Cardiac Remodeling

Objectives: This study was aimed to investigate the impact of the different right ventricularpacing sites on cardiac remodeling and cardiac function and choose the better pacing site.Methods: Selections were based on patients diagnosed with the third degreeatrioventricular block (III°AVB) or sick sinus syndrome (SSS) of the bradycardia in ourhospital from January2008to December2008. They received their first dual chamberpacemaker (DDD). Follow-up information is incomplete and is shorter than three years, and atotal of68cases of pacemaker installation prior to myocardial infarction in patients withpersistent atrial fibrillation met the inclusion criteria. Among them,30cases were III°AVB and38cases were SSS. Patients were divided into two groups, the RVA (cases) and the RVS (cases).The RVS group was furthermore subdivided into three sub-groups, high, medium and lowpacing.Follow-up was carried out at interval of3,6and12months after operation at thespecialist out-patient department which lasted for at least12months. Cardiac ultrasound wasevaluated in the two groups of patients with pacemakers before and after implantation for aperiod of12months.Results: The RVA and RVS group have no difference in LVEF(left ventricular ejectionfraction), LV end-diastolic volume(LV),left atrial diameter(LA), right ventricular diameter(RV),septal thickness(SEP), left ventricular posterior wall thickness(LV POST WALL).But RVSsubgroup results show that at the last follow-up, high septal subgroup LVEF was significantlyhigher than in the low pacing group (66.0±1.4vs.62.0±4.2, vs, P=0.04); high septal subgroupwas significantly higher than in the medium pacing group (66.0±1.4vs.63.0±2.8, P=0.02).Conclusion: This study demonstrated that right ventricular septal pacing superior to rightventricular apical pacing curb cardiac remodeling, improve cardiac function more, and the higherthe pacing site, this effect is more significant. But the two pacing sites cannot reverse mechanical cardiac remodeling and impaired cardiac function. Prompt existing atrioventricular sequentialpacing mode on the basis of the need to seek more optimal pacing site and atrioventricular ofrehabilitation rational pacing mode, such as minimize ventricular pacing, in order to improve theprognosis of patients.