The effects of right ventricular pacing in the heart failure population

Pacemaker implantation remains the sole treatment options for patients <br/>with bradycardia. The devices have evolved over the years, however recent <br/>studies of implantable defibrillators suggested that increased levels of <br/>pacing at the right ventricular apex (the conventional site) may be <br/>associated with worse outcomes in patients with impaired left ventricular <br/>systolic function. <br/>An initial observational database linkage study was performed to investigate <br/>the prevalence of heart failure in patients referred for pacemaker insertion. <br/>This identified a significant portion of patients (19%) had heart failure and <br/>were potentially at risk. Further study was undertaken in patients without <br/>heart failure to investigate the effects of right ventricular (RV) apical pacing <br/>on endothelial function. 22 patients with sino-atrial node disease were <br/>exposed to high degrees of RV pacing and minimal RV pacing in a crossover <br/>study for 1 week each. This demonstrated significant impairment of <br/>endothelial function in the arm with a high degree of RV pacing. <br/>A subsequent study investigated the impact of biventricular pacing <br/>compared to RV pacing again in a cross over design. Patients were implanted with a biventricular device and randomised to RV only or biventricular <br/>pacing. Biventricular pacing was associated with significantly enhanced 6 <br/>minute hall walk distance together with improved quality of life and less <br/>impairment of endothelial function and reduction of hs-CRP when compared <br/>to biventricular pacing. <br/>Finally a further retrospective data-linkage study demonstrated that <br/>angiotensin receptor blocker or angiotensin converting enzyme inhibitor use <br/>was associated with improved mortality and less hospitalisation for heart <br/>failure in patients paced for complete heart block, who were likely to be <br/>exposed to high degrees of right ventricular pacing. <br/>In summary this thesis is a record of my study of the effects of pacemaker <br/>insertion in patients with impaired left ventricular systolic function. My <br/>research has demonstrated the potential detrimental effects of right <br/>ventricular apical pacing and has identified potential therapeutic strategies <br/>of ameliorating these effects.

Name dc:type.qualificationname

Doctor of Medicine

Level dc:type.qualificationlevel

Doctoral Thesis

Grantor dc:publisher.institution

University of Dundee

Year dc:date.issued

2013

Author dc:creator

• Elder, Douglas

Advisor dc:contributor.advisor

• Choy, Anna-Maria

Language dc:language

eng

Identifier

oai:discovery.dundee.ac.uk:studenttheses/fb88ca77-5a1d-49ef-acfe-ca1f9c7db6e6

OAI identifier oai:identifier

oai:discovery.dundee.ac.uk:studenttheses/fb88ca77-5a1d-49ef-acfe-ca1f9c7db6e6