To test or not to test: The challenging dilemma during implantable cardioverter defibrillator implantation procedures Academic Article uri icon


  • reliable and more effective (i.e., they can deliver more energy). At the end of an implantation procedure (surgery) it was routine practice to test the device. Testing meant inducing ventricular fibrillation and letting the device diagnose and treat it (under sedation and with appropriately set backup external defibrillators). Furthermore, to define a defibrillation threshold (to evaluate the minimal energy required for successful defibrillation) multiple inductions of VF2 and subsequent defibrillations were performed during each procedure. To date there is no published randomized clinical trial sufficiently powered to answer the “to test (for defibrillation threshold) or “not to test” dilemma, although there is an ongoing trial, the “Shockless Implant Evaluation” study (SIMPLE show/NCT00800384). Against this background, Codner et al. try to shed some light onto the practice of defibrillation testing, and their results appear in this issue of IMAJ [4]. They retrospectively analyzed 213 patients implanted with an ICD of whom 80 underwent defibrillation safety margin testing (e.g., instead of defining the exact minimal energy required for successful defibrillation, they tested for successful defibrillation at an energy level 10 joules below the device’s maximum, thus performing fewer VF inductions). During a follow-up period of 2 years, there was no difference in overall mortality or in successful defibrillations performed

publication date

  • January 1, 2012