title: High incidence of Pellethane 90A lead malfunction.
abstract: OBJECTIVE
  The long-term performance of Pellethane 80A (P80A) endocardial pacing leads has previously been called into question. We report our experience with an endocardial pacemaker lead with silicone outer and Pellethane 2363-90A (P90) inner insulator.
  
  
  METHODS
  Between November 1993 and March 1998, 129 P90A and 189 non-P90A ventricular leads were implanted. Lead malfunction was defined as > or = 25%) deviation in lead impedance or a two-fold reduction in sensing threshold during follow-up. Sensing and capture thresholds and lead impedance were assessed intraoperatively, immediately postoperatively, at 24 h and 6-12 weeks following implant and semiannually thereafter. Adequacy of lead positioning and lead-header interface were documented radiographically in each case.
  
  
  RESULTS
  During 204 patient years of follow-up, 10/129 (8%) Oscor RX P90A leads malfunctioned. Average time to malfunction was 14 +/- 11 months. During 166 patient years of follow-up, none of the 189 non-P90A ventricular leads met criteria for malfunction (P < 0.05). There was no difference in patient age, sex, and arrhythmia indication between groups. Sensing problems were overcome with pacemaker reprogramming.
  
  
  CONCLUSIONS
  We conclude that Oscor RX passive fixation ventricular leads with external silicone and inner P90A insulation exhibit an 8%, insulation malfunction rate within 14 +/- 11 months of implant. This is significantly higher than non-P90A leads implanted with identical technique and follow-up regimen. More frequent follow up may be warranted in patients with P90A containing leads.
authors.affiliation: State University of New York Health Sciences Center at Stony Brook, Department of Medicine, Division of Cardiology, 11794-8171,USA. roman01866@aol.com
authors.forename: R
authors.initials: R
authors.lastname: Pachulski
authors.forename: M
authors.initials: M
authors.lastname: Zasadil
authors.forename: D
authors.initials: D
authors.lastname: Adkins
authors.forename: B
authors.initials: B
authors.lastname: Hanif
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000503:physiopathology / Q000628:therapy*; D004867:Equipment Design; D004868:Equipment Failure / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000706:statistics & numerical data*; D011140:Polyurethanes / Q000009:adverse effects* / Q000627:therapeutic use*; D012828:Silicones / Q000009:adverse effects / Q000627:therapeutic use; D013997:Time Factors
chemical_list: D011140:Polyurethanes; D012828:Silicones