About this item:

207 Views | 293 Downloads

Author Notes:

Correspondence to: Faisal M. Merchant, MD, Emory University Hospital Midtown, Medical Office Tower, 6th floor, 550 Peachtree Street, Atlanta,GA 30308. E-mail: faisal.merchant@emoryhealthcare.org

Disclosures: Paul Jones receives salary from and has equity interest in Boston Scientific Corporation.

Scott Wehrenberg receives salary from Boston Scientific Corporation.

Leslie Saxon has received research support and honoraria from Boston Scientific Corporation.



  • Science & Technology
  • Life Sciences & Biomedicine
  • Cardiac & Cardiovascular Systems
  • Cardiovascular System & Cardiology
  • defibrillation
  • electrophysiology
  • sudden death
  • TIME

Incidence of Defibrillator Shocks After Elective Generator Exchange Following Uneventful First Battery Life


Journal Title:

Journal of the American Heart Association


Volume 3, Number 6


, Pages e001289-e001289

Type of Work:

Article | Final Publisher PDF


Background: A significant number of implantable cardioverter-defibrillator (ICD) patients do not experience shocks after ICD implant. Elective generator exchange (GE) has been associated with increased risk of infection and ICD lead failure. There is a paucity of contemporary data reporting on shock incidence with replacement devices. Methods and Results: Patients undergoing elective GE (n=24 203) who transmit data remotely via a remote monitoring system were analyzed to determine the incidence of ICD shocks after GE. A total of 16 230 patients (67%) did not experience a shock with the first ICD (group A), and 7973 (33%) received at least 1 shock (group B). Patients in group A were older (71.3 versus 68.8 years, P<0.001) and more often female (71% versus 77% male, P<0.001). Over an average follow-up of 1.9±1.2 years after GE, the proportion of patients with shocks and risk of ICD shocks was lower for those who did not receive a shock during the first battery life (group A: 9.9% versus 27.7%, hazard ratio 0.36, 95% CI 0.34 to 0.38, P<0.001). The cumulative rate of ICD shocks at 5 years after GE was 25.7% in group A and 51.1% in group B. Conclusions: In this large cohort of ICD patients implanted across the United States, two thirds did not receive ICD shock therapy prior to GE. The occurrence of ICD shocks prior to GE is an important predictor of shocks after GE; however, even among those without shocks during first battery life, the incidence of shocks at 5 years following GE is >25%. These data should support informed decision making for patients and physicians at the time of ICD generator end of service.

Copyright information:

© 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

This is an Open Access work distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/).

Creative Commons License

Export to EndNote