title: Insulation defects in Riata implantable cardioverter-defibrillator leads.
abstract: BACKGROUND
  The structures composing implantable cardioverter-defibrillator (ICD) leads have become more complicated and thinner with technological advances. Silicon insulation defects with and without clinically manifested electrical abnormalities have been reported in Riata leads (St. Jude Medical).
  
  
  OBJECTIVE
  The aim of this study was to assess the incidence and clinical implications of insulation defects in Riata leads implanted at our hospital.
  
  
  METHODS
  The subjects included 10 consecutive patients who received 8-French Riata ICD leads with dual-coil conductors (model 1580 or 1581) between 2006 and 2010 at our hospital. Operative records, chest X-rays and interrogation data were reviewed.
  
  
  RESULTS
  In all cases, Atlas+ (St. Jude Medical) was used as an ICD generator and the Riata leads were implanted transvenously and fixed to the right ventricular apex. During a mean follow-up period of 52±9 (36-70) months, chest X-rays revealed insulation defects in Riata leads and conductor wires projecting from the bodies of the Riata leads in two of 10 (20%) patients. One of the patients received inappropriate ICD therapies due to T-wave oversensing based on attenuation of R waves and augmentation of T waves 41 months after implantation. In the other patient, an insulation defect without any clinically manifested electrical troubles was detected 50 months after implantation.
  
  
  CONCLUSIONS
  Riata leads have a high incidence of insulation defects, which may be occasionally accompanied by inappropriate ICD discharges. For patients with Riata leads, careful observation of any changes in the lead-electrical measurements and a routine chest X-ray follow-up are necessary.
authors.affiliation: Division of Cardiology, Niigata University Graduate School of Medical and Dental Sciences, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Sato
authors.forename: Masaomi
authors.initials: M
authors.lastname: Chinushi
authors.forename: Kenichi
authors.initials: K
authors.lastname: Iijima
authors.forename: Daisuke
authors.initials: D
authors.lastname: Izumi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Furushima
mesh_terms: D000328:Adult; D000368:Aged; D053840:Brugada Syndrome / Q000628:therapy; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007564:Japan; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D013902:Radiography, Thoracic; D017180:Tachycardia, Ventricular / Q000628:therapy; D013997:Time Factors; D055815:Young Adult