title: Reducing unnecessary right ventricular pacing with the managed ventricular pacing mode in patients with sinus node disease and AV block.
abstract: BACKGROUND
  Frequent and unnecessary right ventricular apical pacing increases the risk of atrial fibrillation or congestive heart failure. We evaluated a new pacing algorithm, managed ventricular pacing (MVP) which automatically changes modes between AAI/R and DDD/R in patients receiving pacemakers for symptomatic bradycardia.
  
  
  METHODS
  Patients were randomized to the MVP mode or DDD/R mode for 1 month and then crossed over to the alternate pacing modality for an additional month. On completion of the crossover phase, the pacing mode selected was individualized and patients were followed for an additional 4 months.
  
  
  RESULTS
  Of the 129 patients who successfully completed the crossover study, the cumulative percent ventricular pacing was significantly reduced in the MVP mode (median 1.4%) compared to the DDD/R mode (median 89.6%, 94.0% relative reduction; 95% CI 89.3-98.8%, P < 0.001). Patients with sinus node disease (SND, n = 51) when compared to patients with AV block (AVB) (n = 68) experienced a greater reduction in ventricular pacing with the MVP mode compared to the DDD/R mode (median relative reduction 99.1%; 95% CI 97.5-99.9% vs median relative reduction 60.1%; 95% CI 16.7-93.9% P < 0.001). The reduced percent ventricular pacing during MVP was sustained over longer term follow-up.
  
  
  CONCLUSIONS
  The majority of patients with a bradycardia indication for cardiac pacing do not require ventricular pacing most of the time. The MVP mode significantly reduces unnecessary right ventricular pacing. This mode benefits even patients with intermittent AVB and is sustained over longer term follow-up.
authors.affiliation: Libin Cardiovascular Institute of Alberta and Department of Cardiovascular Sciences, University of Calgary and Calgary Health Region, Calgary, Alberta, Canada. amgillis@ucalgary.ca
authors.forename: Anne M
authors.initials: AM
authors.lastname: Gillis
authors.forename: Helmut
authors.initials: H
authors.lastname: Pürerfellner
authors.forename: Carsten W
authors.initials: CW
authors.lastname: Israel
authors.forename: Henri
authors.initials: H
authors.lastname: Sunthorn
authors.forename: Salem
authors.initials: S
authors.lastname: Kacet
authors.forename: Michael
authors.initials: M
authors.lastname: Anelli-Monti
authors.forename: Feng
authors.initials: F
authors.lastname: Tang
authors.forename: Martin
authors.initials: M
authors.lastname: Young
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Boriani
mesh_terms: D000368:Aged; D000465:Algorithms; D001283:Atrioventricular Node / Q000503:physiopathology; D001919:Bradycardia / Q000503:physiopathology / Q000628:therapy*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D018592:Cross-Over Studies; D005260:Female; D006327:Heart Block / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D012804:Sick Sinus Syndrome / Q000503:physiopathology / Q000628:therapy*; D012849:Sinoatrial Node / Q000503:physiopathology; D016896:Treatment Outcome