title: Progressive decrease in amplitude of intracardiac ventricular electrogram and higher left ventricular ejection fraction are associated with conductors' externalization in Riata leads.
abstract: OBJECTIVE
  Increased rates of structural abnormalities including externalized conductors have been reported in the Riata family of implantable cardioverter-defibrillator leads (St Jude Medical). Little is known about their reliability and the time lag for emergence of functional or structural abnormalities.
  
  
  RESULTS
  Thirty-six patients who received small-caliber leads of the Riata family and who completed face-profile flouroscopies, repeated at every 6 months were included. We assessed the prevalence of conductors' externalization and its relation to abnormal electrical parameters or adverse events. Thirty-six patients, mean age = 64 ± 10 years, with at least 7-month completed fluoroscopy follow-up were included in the analysis. Externalized conductors were identified in 12 (33%) patients after a 53-month (13-114) mean delay. A higher left ventricular ejection fraction (LVEF): 47 ± 13 vs. 33 ± 12%, P = 0.04, and a progressive decrease (≥30% of the initial value) in amplitude of ventricular electrogram 9/12 (75%) vs. 4/24 (17%), P = 0.03 were independently associated with the fluoroscopic failures. Detection of the conductors' externalization was preceded by an electrical lead abnormality in 10 (83%) patients.
  
  
  CONCLUSIONS
  Repeated face-profile fluoroscopies allowed detection of conductors' externalization in 33% of patients implanted with Riata leads. Better LVEF and a progressive decrease in amplitude of intracardiac ventricular electrogram were independently associated with externalized conductors. The structural abnormality was preceded by an electrical lead dysfunction 83% of patients.
authors: Department of Cardiac Arrhythmia, Cardiology Unit, Picardie University Hospital, Boulevard Laennec, 80000 Amiens, France. kubala.maciej@chu-amiens.fr
authors: Maciej
authors: M
authors: Kubala
authors: Sarah
authors: S
authors: Traullé
authors: Laurent
authors: L
authors: Leborgne
authors: Jean-Sylvain
authors: JS
authors: Hermida
mesh_terms: D000368:Aged; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004553:Electric Conductivity; D004556:Electric Injuries / Q000175:diagnosis* / Q000209:etiology*; D015716:Electrocardiography, Ambulatory; D004567:Electrodes, Implanted / Q000009:adverse effects*; D004867:Equipment Design; D004868:Equipment Failure; D019544:Equipment Failure Analysis; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000517:prevention & control*; D006801:Humans; D008297:Male; D013318:Stroke Volume; D016896:Treatment Outcome
keywords: Fluoroscopy; Implantable cardioverter-defibrillator; Insulation; Lead failure; Riata lead