Pacemaker implantation remains the sole treatment options for patientswith bradycardia. The devices have evolved over the years, however recentstudies of implantable defibrillators suggested that increased levels ofpacing at the right ventricular apex (the conventional site) may beassociated with worse outcomes in patients with impaired left ventricularsystolic function.An initial observational database linkage study was performed to investigatethe prevalence of heart failure in patients referred for pacemaker insertion.This identified a significant portion of patients (19%) had heart failure andwere potentially at risk. Further study was undertaken in patients withoutheart failure to investigate the effects of right ventricular (RV) apical pacingon endothelial function. 22 patients with sino-atrial node disease wereexposed to high degrees of RV pacing and minimal RV pacing in a crossoverstudy for 1 week each. This demonstrated significant impairment ofendothelial function in the arm with a high degree of RV pacing.A subsequent study investigated the impact of biventricular pacingcompared to RV pacing again in a cross over design. Patients were implanted with a biventricular device and randomised to RV only or biventricularpacing. Biventricular pacing was associated with significantly enhanced 6minute hall walk distance together with improved quality of life and lessimpairment of endothelial function and reduction of hs-CRP when comparedto biventricular pacing.Finally a further retrospective data-linkage study demonstrated thatangiotensin receptor blocker or angiotensin converting enzyme inhibitor usewas associated with improved mortality and less hospitalisation for heartfailure in patients paced for complete heart block, who were likely to beexposed to high degrees of right ventricular pacing.In summary this thesis is a record of my study of the effects of pacemakerinsertion in patients with impaired left ventricular systolic function. Myresearch has demonstrated the potential detrimental effects of rightventricular apical pacing and has identified potential therapeutic strategiesof ameliorating these effects.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:578954 |
| Date | January 2013 |
| Creators | Elder, Douglas |
| Contributors | Choy, Anna |
| Publisher | University of Dundee |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://discovery.dundee.ac.uk/en/studentTheses/fb88ca77-5a1d-49ef-acfe-ca1f9c7db6e6 |
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