title: Inappropriate shocks in patients with Fidelis® lead fractures: impact of remote monitoring and the lead integrity algorithm.
abstract: BACKGROUND
  The role of remote monitoring combined with lead integrity algorithm (LIA) in patients with Fidelis (Medtronic Inc., Minneapolis, MN, USA) lead fractures is not well defined.
  
  
  METHODS
  We retrospectively identified patients with Fidelis lead fractures at our institution, documenting all pertinent data (remote monitoring use, clinical presentation, lead fracture diagnosis criteria). Patients were classified into subgroups based on the type of home monitoring and whether LIA was uploaded before lead fracture. Subgroups were compared based on delivery of inappropriate shocks (IS).
  
  
  RESULTS
  A total of 131 patients (mean age 62 ± 16 years, 70% male, 69% primary prevention implants) were followed until lead fracture (average 32 ± 12 months). IS were delivered in 21% of patients (n = 11/52) with LIA versus 52% (n = 41/79) without LIA, P < 0.001. LIA significantly decreased the number of IS (2.1 ± 1.0 IS vs 7.9 ± 12 IS, P < 0.001) and significantly increased the number of patients diagnosed through audible alert (P < 0.001). Wireless monitoring significantly decreased the time interval to reprogram defibrillators OFF (mean 1.5 ± 1 days vs 15.6 ± 18 days with nonwireless CareLink [Medtronic Inc.] and 12.4 ± 20 days without CareLink, P < 0.001); 14% of patients with LIA and wireless monitoring combined received IS. Without LIA, 63% of patients with wireless monitoring received IS.
  
  
  CONCLUSIONS
  This study confirms that LIA significantly decreases IS therapy in patients with Fidelis lead fractures. Wireless technology enhances LIA benefits by significantly shortening time to reprogram defibrillators. However, despite the "best scenario" of combining LIA and wireless monitoring, 14% of patients with lead fractures still get IS. Further refinements of detection algorithms are required to eliminate this significant clinical problem.
authors.affiliation: Aurora Cardiovascular Services, Aurora Sinai/Aurora St. Luke's Medical Centers, University of Wisconsin School of Medicine and Public Health, Milwaukee, Wisconsin, USA.
authors.forename: Zalmen
authors.initials: Z
authors.lastname: Blanck
authors.forename: Kathi
authors.initials: K
authors.lastname: Axtell
authors.forename: Kathy
authors.initials: K
authors.lastname: Brodhagen
authors.forename: Laura
authors.initials: L
authors.lastname: O'Hearn
authors.forename: Tammy
authors.initials: T
authors.lastname: Albelo
authors.forename: Cheryl
authors.initials: C
authors.lastname: Ceretto
authors.forename: Anwer
authors.initials: A
authors.lastname: Dhala
authors.forename: Jasbir
authors.initials: J
authors.lastname: Sra
authors.forename: Masood
authors.initials: M
authors.lastname: Akhtar
mesh_terms: D000368:Aged; D000465:Algorithms; D056902:Clinical Alarms; D017147:Defibrillators, Implantable; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted; D012984:Software; D013686:Telemetry; D013997:Time Factors; D014922:Wisconsin