title: Clinical study of interference with cardiac pacemakers by a magnetic field at power line frequencies.
abstract: OBJECTIVE
  This study examined the risk of interference by high magnetic flux density with permanent pacemakers.
  
  
  BACKGROUND
  Several forms of electromagnetic energy may interfere with the functions of implanted pacemakers. No clinical study has reported specific and relevant information pertaining to magnetic fields near power lines or electrical appliances.
  
  
  METHODS
  A total of 250 consecutive tests were performed in 245 recipients of permanent pacemakers during 12-lead electrocardiographic monitoring. A dedicated exposure system generated a 50-Hz frequency and maximum 100-microT flux density, while the electrical field was kept at values on the order of 0.10 V/m.
  
  
  RESULTS
  A switch to the asynchronous mode was recorded in three patients with devices programmed in the unipolar sensing configuration. A sustained mode switch was followed by symptomatic pacing inhibition in one patient. No effect on devices programmed in bipolar sensing was observed, except for a single interaction with a specific capture monitoring algorithm.
  
  
  CONCLUSIONS
  The overall incidence of interaction by a magnetic field was low in patients tested with a wide variety of conventionally programmed pacemaker models. A magnetic field pulsed at power frequency can cause a mode switch and pacing inhibition in patients with devices programmed in the unipolar sensing configuration. The risk of interference appears negligible in patients with bipolar sensing programming.
authors.affiliation: Department of Cardiology, Centre Hospitalier Universitaire Nord, Marseille, France. alexandre.trigano@mail.ap-hm.fr
authors.forename: Alexandre
authors.initials: A
authors.lastname: Trigano
authors.forename: Olivier
authors.initials: O
authors.lastname: Blandeau
authors.forename: Martine
authors.initials: M
authors.lastname: Souques
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Gernez
authors.forename: Isabelle
authors.initials: I
authors.lastname: Magne
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001919:Bradycardia / Q000473:pathology / Q000601:surgery; D002304:Cardiac Pacing, Artificial; D004562:Electrocardiography; D004574:Electromagnetic Fields; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000473:pathology / Q000601:surgery; D006329:Heart Conduction System / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D016896:Treatment Outcome