title: Riata silicone defibrillation lead with normal electrical measures at routine ambulatory check: The role of high-voltage shock testing.
abstract: OBJECTIVE
  To describe our experience with shock testing for the evaluation of patients with Riata™ leads.
  
  
  METHODS
  Among 51 patients with normal baseline electrical parameters, 20 died during follow-up. Of the remaining 31 patients, 15 underwent the test: In 10 cases a defibrillation testing with ventricular fibrillation (VF) induction and in 5 cases a R-wave-synchronized shock (> 20 J, without inducing VF). The test was performed under sedation with Midazolam.
  
  
  RESULTS
  Twelve patients (80%) had a normal behavior during shock testing: In 8 cases induced VF was correctly detected and treated; in 4 cases of R-wave-synchronized shock electrical parameters remained stable and normal. Three patients (20%) failed the test. One patient with externalized conductors showed a sudden drop of high-voltage impedance (< 10 Ohm) after a 25 J R-wave-synchronized shock. Two other patients with externalized conductors, undergoing defibrillation testing, showed a short-circuit during shock delivery and the implantable cardioverter defibrillator was unable to interrupt VF.
  
  
  CONCLUSIONS
  In Riata™ leads the delivery of a low current during routine measurement of high-voltage impedance may not reveal a small short circuit, that can only be evident by attempting to deliver a true shock, either for spontaneous arrhythmias or in the context of a shock testing.
authors.affiliation: Elia De Maria, Ambra Borghi, Lorenzo Bonetti, Pier Luigi Fontana, Stefano Cappelli, Cardiology Unit, Ramazzini Hospital, 41012 Carpi (Modena), Italy.
authors.forename: Elia
authors.initials: E
authors.lastname: De Maria
authors.affiliation: Elia De Maria, Ambra Borghi, Lorenzo Bonetti, Pier Luigi Fontana, Stefano Cappelli, Cardiology Unit, Ramazzini Hospital, 41012 Carpi (Modena), Italy.
authors.forename: Ambra
authors.initials: A
authors.lastname: Borghi
authors.affiliation: Elia De Maria, Ambra Borghi, Lorenzo Bonetti, Pier Luigi Fontana, Stefano Cappelli, Cardiology Unit, Ramazzini Hospital, 41012 Carpi (Modena), Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Bonetti
authors.affiliation: Elia De Maria, Ambra Borghi, Lorenzo Bonetti, Pier Luigi Fontana, Stefano Cappelli, Cardiology Unit, Ramazzini Hospital, 41012 Carpi (Modena), Italy.
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Fontana
authors.affiliation: Elia De Maria, Ambra Borghi, Lorenzo Bonetti, Pier Luigi Fontana, Stefano Cappelli, Cardiology Unit, Ramazzini Hospital, 41012 Carpi (Modena), Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Cappelli
keywords: Defibrillation testing; Externalized conductors; Implantable cardioverter defibrillator; Lead failure; Riata™ lead