title: Premature Trigger of ERI in Medtronic EnRhythm Devices.
abstract: BACKGROUND
  Medical technology has made significant advances over the last few decades with smaller and more dynamic pacemakers. However, technical failures leading to premature replacement is a cause of concern. We present a series of Medtronic EnRhythm devices that reached premature elective replacement indicator (ERI).
  
  
  METHODS
  The database of Centre of Heart Rhythm Disorders was searched for EnRhythm device implantation from 2006 to 2011. Battery depletion <8.5 years was considered premature considering the projected average longevity to be 8.5-10.5 years. An unexpected premature ERI was defined when it was reached within 3 months of last normal check. Device follow-up was conducted every 3 months after advisory.
  
  
  RESULTS
  A total of 88 EnRhythm pacemakers were implanted. Over a median follow-up of 6.2 years (range: 0.3-9.2), 39 (44.3%) EnRhythm devices reached premature ERI. In 11 (28%), ERI was not recognized and patients were being investigated for other causes of unsteadiness or dyspnea prior to device check. Notably, three (7%) patients had premature ERI < 3.5 years. Ten (25.6%) had sudden and unexpected premature ERI. While asynchronous pacing was observed, there were no cases of absence of pacing.
  
  
  CONCLUSIONS
  The rate of premature ERI for EnRhythm devices was 44.3%, significantly higher than reported by the manufacturer. Of concern, a sizeable proportion occurred unexpectedly, warranting more frequent reviews and empirical replacement in some patients. With the experience of the EnRhythm, appropriate monitoring strategies are recommended for future advisories.
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Melissa E
authors.initials: ME
authors.lastname: Middeldorp
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Mahajan
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Adrian D
authors.initials: AD
authors.lastname: Elliott
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Rajeev K
authors.initials: RK
authors.lastname: Pathak
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Darragh
authors.initials: D
authors.lastname: Twomey
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Lauren
authors.initials: L
authors.lastname: Wilson
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Simon
authors.initials: S
authors.lastname: Stolcman
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Dian A
authors.initials: DA
authors.lastname: Munawar
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Sharath
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Dennis H
authors.initials: DH
authors.lastname: Lau
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Prashanthan
authors.initials: P
authors.lastname: Sanders
mesh_terms: D000368:Aged; D020878:Device Removal / Q000706:statistics & numerical data*; D011211:Electric Power Supplies / Q000706:statistics & numerical data*; D004867:Equipment Design; D004868:Equipment Failure / Q000706:statistics & numerical data*; D019544:Equipment Failure Analysis / Q000706:statistics & numerical data*; D004869:Equipment Safety / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D057052:Medical Device Recalls; D010138:Pacemaker, Artificial / Q000706:statistics & numerical data*; D061214:Patient Safety / Q000706:statistics & numerical data; D013021:South Australia / Q000453:epidemiology
keywords: device recalls; elective replacement indicator; pacemaker; remote monitoring