title: Effect of right ventricular pacing lead site on left ventricular function in patients with high-grade atrioventricular block: results of the Protect-Pace study.
abstract: OBJECTIVE
  Chronic right ventricle (RV) apical (RVA) pacing is standard treatment for an atrioventricular (AV) block but may be deleterious to left ventricle (LV) systolic function. Previous clinical studies of non-apical pacing have produced conflicting results. The aim of this randomized, prospective, international, multicentre trial was to compare change in LV ejection fraction (LVEF) between right ventricular apical and high septal (RVHS) pacing over a 2-year study period.
  
  
  RESULTS
  We randomized 240 patients (age 74 ± 11 years, 67% male) with a high-grade AV block requiring >90% ventricular pacing and preserved baseline LVEF >50%, to receive pacing at the RVA (n = 120) or RVHS (n = 120). At 2 years, LVEF decreased in both the RVA (57 ± 9 to 55 ± 9%, P = 0.047) and the RVHS groups (56 ± 10 to 54 ± 10%, P = 0.0003). However, there was no significant difference in intra-patient change in LVEF between confirmed RVA (n = 85) and RVHS (n = 83) lead position (P = 0.43). There were no significant differences in heart failure hospitalization, mortality, the burden of atrial fibrillation, or plasma brain natriutetic peptide levels between the two groups. A significantly greater time was required to place the lead in the RVHS position (70 ± 25 vs. 56 ± 24 min, P < 0.0001) with longer fluoroscopy times (11 ± 7 vs. 5 ± 4 min, P < 0.0001).
  
  
  CONCLUSIONS
  In patients with a high-grade AV block and preserved LV function requiring a high percentage of ventricular pacing, RVHS pacing does not provide a protective effect on left ventricular function over RVA pacing in the first 2 years.
  ClinicalTrials.gov number NCT00461734.
authors.affiliation: Department of Cardiology, The University of Queensland and Princess Alexandra Hospital, Ipswich Road, Wolloongabba, Brisbane 4102, Queensland, Australia gerald.kaye@health.qld.gov.au.
authors.forename: Gerald C
authors.initials: GC
authors.lastname: Kaye
authors.affiliation: The James Cook University Hospital, Middlesbrough, UK.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Linker
authors.affiliation: Menzies Research Institute Tasmania, Hobart, Australia.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Marwick
authors.affiliation: Medtronic Ltd., Hertfordshire, UK.
authors.forename: Lucy
authors.initials: L
authors.lastname: Pollock
authors.affiliation: Medtronic Ltd., Hertfordshire, UK.
authors.forename: Laura
authors.initials: L
authors.lastname: Graham
authors.affiliation: Medtronic, Minneapolis, MN, USA.
authors.forename: Erika
authors.initials: E
authors.lastname: Pouliot
authors.affiliation: St George's Medical School, London, UK.
authors.forename: Jan
authors.initials: J
authors.lastname: Poloniecki
authors.affiliation: The Medical School, University of Birmingham, Birmingham, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Gammage
mesh_terms: D000368:Aged; D054537:Atrioventricular Block / Q000503:physiopathology / Q000628:therapy*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000209:etiology; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D019919:Prosthesis Implantation / Q000379:methods; D016037:Single-Blind Method; D013318:Stroke Volume / Q000502:physiology; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology / Q000628:therapy*; D016277:Ventricular Function, Left / Q000502:physiology
keywords: Left ventricular function; Right ventricular apical pacing; Right ventricular high septal pacing; Select site pacing