title: Electromagnetic interference of avalanche transceivers with cardiac pacemakers and implantable cardioverter defibrillators.
abstract: BACKGROUND
  Avalanche transceivers are essentials tools in locating persons who were buried by an avalanche. In the past few years, avalanche transceivers have become widely available and affordable, but it is largely unknown whether they are a source of electromagnetic interference for implanted cardiac devices. We aimed to determine the potential interaction between avalanche transceivers and pacemakers or implantable cardioverter defibrillators (ICDs).
  
  
  METHODS
  One hundred and one patients, 41 with pacemakers and 60 with ICDs, were enrolled (mean age 66 ± 15 years). Four avalanche transceivers (Pieps DSP [Pieps GmbH, Lebring, Austria], Ortovox x1, Ortovox m2, and Ortovox f1 [Otovox Sportartikel GmbH, Taufkirchen, Germany]) were evaluated in transmit as well as in receive mode. Surface electrocardiograms, intracardiac electrograms, and marker channels were continuously recorded and observed by an experienced physician. Electromagnetic interference events were categorized as direct interference with the function of the implanted device itself or as interference with the telemetric communication without compromising device function.
  
  
  RESULTS
  Among all patients, there was no interference with the intrinsic function of their pacemakers or ICDs. A total of 120 episodes of telemetry interference occurred in 48% of the patients. Of those episodes, 112 of 404 (28%) were observed in transmit and eight of 404 (2%) in receive mode (P < 0.0001). The digital avalanche transceiver (Pieps DSP) was associated with significantly less telemetry interference (20/202; 10%) than the analog transceiver (Ortovox f1) (39/202; 19%) (P = 0.0108).
  
  
  CONCLUSIONS
  Avalanche transceivers are safe for patients with pacemakers and ICDs. Despite the observed telemetry interferences, the intrinsic function of the implanted devices was never compromised.
authors.affiliation: Department of Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Dorenkamp
authors.forename: Florian
authors.initials: F
authors.lastname: Blaschke
authors.forename: Kathleen
authors.initials: K
authors.lastname: Voigt
authors.forename: Eckart
authors.initials: E
authors.lastname: Fleck
authors.forename: Stephan
authors.initials: S
authors.lastname: Goetze
authors.forename: Mattias
authors.initials: M
authors.lastname: Roser
mesh_terms: D000368:Aged; D016477:Artifacts; D055875:Avalanches; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D019544:Equipment Failure Analysis / Q000706:statistics & numerical data*; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial / Q000706:statistics & numerical data*; D010355:Patient Identification Systems / Q000706:statistics & numerical data*; D011845:Radio / Q000295:instrumentation* / Q000706:statistics & numerical data
keywords: avalanche transceiver; electromagnetic interference; implantable cardioverter defibrillator; pacemaker