title: Insight into the mechanism of failure of the Riata lead under advisory.
abstract: BACKGROUND
  Cable externalization and insulation abrasion are known to occur with the St Jude Medical Riata leads under advisory. The distribution of these abnormalities and how they relate to clinical presentation have not been well described.
  
  
  OBJECTIVE
  In this study, we sought to determine the relationship between structural lead failure and clinical presentation by using the analysis of returned Riata products in Canada.
  
  
  METHODS
  The analyses of returned Riata products in Canada were obtained from St Jude Medical, Sylmar, CA. These data were correlated with the clinical presentation of patients just before lead removal from service.
  
  
  RESULTS
  As of May 1, 2013, there were 263 returned Riata leads in Canada. Of these, 43 (16.8%) were found to have insulation abrasion that was due to either lead-can or lead-other device interaction (70%) or inside-out abrasion (27.9%). The predilection of lead-to-can abrasion was seen in the Riata 7-F leads (84.2% vs 58.4%; P = .07), while inside-out abrasion was more common in the Riata 8-F leads (37.5% vs 15.8%; P = .12). Electrical abnormalities were frequent (20 of 31 [65.4%]) and most often due to electrical noise (45.2%), although inappropriate shocks were present (25.8%). Death occurred in 1 of 43 (2.3%) of those patients with an insulation defect in the lead-can abrasion group.
  
  
  CONCLUSIONS
  Lead-can abrasion is the most common form of insulation defect in the Riata group of leads under advisory. Management of this group of leads under advisory should not neglect the issue of lead-can abrasion, in addition to detection of cable externalization.
authors.affiliation: QEII Health Sciences Center, Halifax, Nova Scotia, Canada. Electronic address: parkashr@cdha.nshealth.ca.
authors.forename: Ratika
authors.initials: R
authors.lastname: Parkash
authors.affiliation: St. Paul's Hospital, Vancouver, British Columbia, Canada.
authors.forename: Stanley
authors.initials: S
authors.lastname: Tung
authors.affiliation: Quebec Heart Institute, Laval Hospital, Quebec City, Quebec, Canada.
authors.forename: Jean
authors.initials: J
authors.lastname: Champagne
authors.affiliation: Hamilton Health Sciences Center, Hamilton, Ontario Canada.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Healey
authors.affiliation: Montreal Heart Institute, Montreal, Quebec, Canada.
authors.forename: Bernard
authors.initials: B
authors.lastname: Thibault
authors.affiliation: University Health Network, Toronto, Ontario, Canada.
authors.forename: Douglas
authors.initials: D
authors.lastname: Cameron
authors.affiliation: London Health Sciences Center, London, Ontario, Canada.
authors.forename: Anthony
authors.initials: A
authors.lastname: Tang
authors.affiliation: Memorial University Health Sciences Center, St John's Newfoundland, Canada.
authors.forename: Sean
authors.initials: S
authors.lastname: Connors
authors.affiliation: Southlake Regional Health Centre, Newmarket, Ontario, Canada.
authors.forename: Marianne
authors.initials: M
authors.lastname: Beardsall
authors.affiliation: St Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Iqwal
authors.initials: I
authors.lastname: Mangat
authors.affiliation: Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Quebec, Canada.
authors.forename: Felix
authors.initials: F
authors.lastname: Ayala-Paredes
authors.affiliation: Saint John Regional Hospital, Saint John, New Brunswick, Canada.
authors.forename: Satish
authors.initials: S
authors.lastname: Toal
authors.affiliation: Libin Cardiovascular Institute, Calgary, Alberta, Canada.
authors.forename: Derek
authors.initials: D
authors.lastname: Exner
authors.affiliation: London Health Sciences Center, London, Ontario, Canada.
authors.forename: Raymond
authors.initials: R
authors.lastname: Yee
authors.affiliation: University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Krahn
mesh_terms: D000368:Aged; D002170:Canada; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004553:Electric Conductivity / Q000009:adverse effects* / Q000627:therapeutic use; D004567:Electrodes, Implanted / Q000009:adverse effects*; D004867:Equipment Design / Q000009:adverse effects*; D004868:Equipment Failure / Q000706:statistics & numerical data*; D019544:Equipment Failure Analysis / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011358:Product Surveillance, Postmarketing
keywords: Device advisory; Implantable cardioverter-defibrillator; Lead failure