title: Real world evaluation of dual-zone ICD and CRT-D programming compared to single-zone programming: the ALTITUDE REDUCES study.
abstract: BACKGROUND
  We evaluated the frequency of appropriate and inappropriate shocks and survival in patients using dual-zone programming versus single-zone programming.
  
  
  RESULTS
  For the ALTITUDE REDUCES study, patients were followed for 1.6 ± 1.1 years. The 12-month incidence of any shock was lower for dual-versus single-zone programmed detection at rates ≤170 bpm and between 170-200 bpm (P < 0.001). Appropriate shock rates at 1 year were also lower with dual-zone programming in these rate intervals (single zone 9.1%, 5.4%, P < 0.001, dual zone 6.7%, 4.7%, P < 0.02). There were no detectable differences between single- and dual-zone shock incidence at detection rates ≥ 200 bpm (P = 0.14). Inappropriate shock incidence was less with dual- versus single-zone detection at all detect rates <200 bpm, but not at rates ≥200 bpm (P < 0.001, P = 0.37). The lowest risk of appropriate and inappropriate shock was associated with dual-zone programming and detection rates ≥200 bpm (2.1%). Dual-zone detection was associated with more nonsustained and diverted therapy episodes but these patients did not have an increased risk of death compared to patients with single-zone programming. Patients programmed to low detection rate, single-zone detection and shock-only therapy also had the highest preshock mortality risk (P = 0.05).
  
  
  CONCLUSIONS
  Shock incidence is lowest with either single- or dual-zone detection ≥200 bpm. For detection rates <200 bpm, dual-zone programming is associated with a reduction in the incidence of total shocks, appropriate shocks, and inappropriate shocks.
authors.affiliation: Cardiology Associates of Northeast Arkansas, Jonesboro, Arkansas, USA.
authors.forename: F Roosevelt
authors.initials: FR
authors.lastname: Gilliam
authors.forename: David L
authors.initials: DL
authors.lastname: Hayes
authors.forename: John P
authors.initials: JP
authors.lastname: Boehmer
authors.forename: John
authors.initials: J
authors.lastname: Day
authors.forename: Paul A
authors.initials: PA
authors.lastname: Heidenreich
authors.forename: Milan
authors.initials: M
authors.lastname: Seth
authors.forename: Paul W
authors.initials: PW
authors.lastname: Jones
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Stein
authors.forename: Leslie A
authors.initials: LA
authors.lastname: Saxon
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D017147:Defibrillators, Implantable / Q000009:adverse effects* / Q000592:standards*; D004868:Equipment Failure; D005500:Follow-Up Studies; D006801:Humans; D011446:Prospective Studies; D012189:Retrospective Studies; D017180:Tachycardia, Ventricular / Q000453:epidemiology* / Q000503:physiopathology / Q000628:therapy*