title: Comparison of two strategies to reduce ventricular pacing in pacemaker patients.
abstract: BACKGROUND
  Managed Ventricular Pacing (MVP) and Search AV+ (SAV+) are two pacing algorithms designed to reduce ventricular pacing. MVP promotes conduction by operating in AAI/R mode with backup ventricular pacing during atrioventricular block (AVB). SAV+ operates in DDD/R mode with a nominal AV extension of 290 ms during atrial sensing and 320 ms during atrial pacing. The reduction in ventricular pacing was compared with these two algorithms in pacemaker patients.
  
  
  METHODS
  The EnRhythm and EnPulse clinical studies assessed the percentage of ventricular pacing (%VP) after 1 month. Each patient's AVB status was assigned using the following hierarchical categories: persistent third-degree AVB (p3AVB), episodic third-degree AVB (e3AVB), second-degree AVB (2AVB), first-degree AVB (1AVB), and no AVB (nAVB). The%VP was tabulated for each AVB status category.
  
  
  RESULTS
  Data were available from 322 patients of whom 129 received DDD(R) pacing with the MVP algorithm activated and 193 patients with DDD(R) pacing and the SAV+ function activated, each for a month period. MVP resulted in a significantly lower median%VP than SAV+ in all AVB categories except for p3AVB: nAVB (0.3 vs 2.9, P < 0.0001), 1AVB (0.9% vs 80.6%, P < 0.0001), 2AVB (37.6 vs 99.3, P< 0.002), e3AVB (1.2 vs 42.2, P = 0.02), p3AVB (98.9 vs 100, P = 1.00).
  
  
  CONCLUSIONS
  MVP resulted in a greater reduction in%VP than SAV+ across all patient groups except persistent third-degree AV block. The greatest reduction in%VP was observed in patients with mildly impaired AV conduction.
authors.affiliation: Krankenhaus der Elisabethinen, Academic Teaching Hospital, Linz, Austria.
authors.forename: Helmut
authors.initials: H
authors.lastname: Pürerfellner
authors.forename: Johan
authors.initials: J
authors.lastname: Brandt
authors.forename: Carsten
authors.initials: C
authors.lastname: Israel
authors.forename: Todd
authors.initials: T
authors.lastname: Sheldon
authors.forename: James
authors.initials: J
authors.lastname: Johnson
authors.forename: Karlheinz
authors.initials: K
authors.lastname: Tscheliessnigg
authors.forename: Johannes
authors.initials: J
authors.lastname: Sperzel
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Boriani
authors.forename: Andrea
authors.initials: A
authors.lastname: Puglisi
authors.forename: Goran
authors.initials: G
authors.lastname: Milasinovic
mesh_terms: D000465:Algorithms; D000704:Analysis of Variance; D001283:Atrioventricular Node / Q000503:physiopathology*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002986:Clinical Trials as Topic; D005260:Female; D006327:Heart Block / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male