title: Clinical impact of defibrillation testing at the time  of implantable cardioverter-defibrillator insertion.
abstract: BACKGROUND
  Ventricular fibrillation is routinely induced during implantable cardioverter-defibrillator insertion to assess defibrillator performance, but this strategy is experiencing a progressive decline. We aimed to assess the efficacy of defibrillator therapies and long-term outcome in a cohort of patients that underwent defibrillator implantation with and without defibrillation testing.
  
  
  METHODS
  Retrospective observational series of consecutive patients undergoing initial defibrillator insertion or generator replacement. We registered spontaneous ventricular arrhythmias incidence and therapy efficacy, and mortality.
  
  
  RESULTS
  A total of 545 patients underwent defibrillator implantation (111 with and 434 without defibrillation testing). After 19 (range 9-31) months of follow-up, the death rate per observation year (4% vs. 4%; p = 0.91) and the rate of patients with defibrillator-treated ventricular arrhythmic events per observation year (with test: 10% vs. without test: 12%; p = 0.46) were similar. The generalized estimating equations-adjusted first shock probability of success in patients with test (95%; CI 88-100%) vs. without test (98%; CI 96-100%; p = 0.42) and the proportion of successful antitachycardia therapies (with test: 87% vs. without test: 80%; p = 0.35) were similar between groups. There was no difference in the annualized rate of failed first shock per patient and per shocked patient between groups (5% vs. 4%; p = 0.94).
  
  
  CONCLUSIONS
  In this observational study, that included an unselected population of patients with a defibrillator, no difference was found in overall mortality, first shock efficacy and rate of failed shocks regardless of whether defibrillation testing was performed or not.
authors.forename: Claudio
authors.initials: C
authors.lastname: Hadid
authors.forename: Felipe
authors.initials: F
authors.lastname: Atienza
authors.forename: Boris
authors.initials: B
authors.lastname: Strasberg
authors.forename: Ángel
authors.initials: Á
authors.lastname: Arenal
authors.forename: Pablo
authors.initials: P
authors.lastname: Codner
authors.forename: Esteban
authors.initials: E
authors.lastname: González-Torrecilla
authors.forename: Tomás
authors.initials: T
authors.lastname: Datino
authors.forename: Tamara
authors.initials: T
authors.lastname: Percal
authors.forename: Jesús
authors.initials: J
authors.lastname: Almendral
authors.forename: Mercedes
authors.initials: M
authors.lastname: Ortiz
authors.forename: Raphael
authors.initials: R
authors.lastname: Martins
authors.forename: Nieves
authors.initials: N
authors.lastname: Martinez-Alzamora
authors.forename: Francisco
authors.initials: F
authors.lastname: Fernandez Aviles
mesh_terms: D000368:Aged; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D004554:Electric Countershock / Q000009:adverse effects / Q000295:instrumentation* / Q000401:mortality; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D007430:Intraoperative Care / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D011475:Prosthesis Failure; D019919:Prosthesis Implantation / Q000295:instrumentation*; D012189:Retrospective Studies; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*