title: Unpredictable battery depletion of St Jude Atlas II and Atlas+ II HF implantable cardioverter-defibrillators.
abstract: BACKGROUND
  Predictable progression to battery depletion is necessary for device management in patients with pacemakers or implantable cardioverter-defibrillators, particularly in patients who either are pacemaker dependent or have required implantable cardioverter-defibrillator therapies.
  
  
  OBJECTIVE
  To determine the incidence and characteristics of unexpected battery depletion in patients implanted with a cardiac resynchronization therapy - defibrillator (CRT-D) device.
  
  
  METHODS
  All patients with a St Jude Atlas+ HF or Atlas II HF CRT-D device implanted between 2004 and 2007 at the Massachusetts General Hospital and the Nashville VA Medical Center (Vanderbilt University) were studied. All patients with early generator depletion (transition of generator voltage above specified elective replacement indicator [ERI] to end of life [EOL] in less than 90 days) were evaluated further.
  
  
  RESULTS
  Eight cases (mean age 69.6 ± 9 years) with abrupt battery depletion were identified among 191 patients (4.2%) implanted with a St Jude Atlas CRT-D device. The longevity of 8 premature depletion devices was 46.4 ± 10 months (median 45 months). The battery voltage in these 8 devices decreased from a mean of 2.48 ± 0.03 V (above ERI) to 2.3 ± 0.08 V (below ERI) over 33.3 ± 23 days (range 1-59 days; median 38.5 days). One device reached EOL status within 1 day of having battery voltage above ERI and another device within 12 days.
  
  
  CONCLUSIONS
  The incidence of abrupt battery depletion was 4.2% in patients implanted with a St Jude Atlas CRT-D device. No common mechanism has been identified for this failure. Close monitoring of battery voltage and timely generator replacement are required in patients with these devices.
authors.affiliation: Cardiac Arrhythmia Service, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Cevher
authors.initials: C
authors.lastname: Ozcan
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Rottman
authors.forename: E Kevin
authors.initials: EK
authors.lastname: Heist
authors.forename: Mary L
authors.initials: ML
authors.lastname: Guy
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Ellinor
authors.forename: Jagmeet
authors.initials: J
authors.lastname: Singh
authors.forename: David J
authors.initials: DJ
authors.lastname: Milan
authors.forename: Stephan B
authors.initials: SB
authors.lastname: Danik
authors.forename: Conor D
authors.initials: CD
authors.lastname: Barrett
authors.forename: Moussa
authors.initials: M
authors.lastname: Mansour
authors.forename: Jeremy N
authors.initials: JN
authors.lastname: Ruskin
authors.forename: Theofanie
authors.initials: T
authors.lastname: Mela
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D011211:Electric Power Supplies / Q000706:statistics & numerical data*; D004868:Equipment Failure / Q000706:statistics & numerical data*; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged