Get access

Novel Electrode Design for Potentially Painless Internal Defibrillation Also Allows for Successful External Defibrillation

Authors

  • VENKU JAYANTI Ph.D,

    1. Departments of Medicine and Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
    Search for more papers by this author
  • MENEKHEM M. ZVIMAN Ph.D,

    1. Departments of Medicine and Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
    Search for more papers by this author
  • SAMAN NAZARIAN M.D.,

    1. Departments of Medicine and Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
    Search for more papers by this author
  • HENRY R. HALPERIN M.D., M.A.,

    1. Departments of Medicine and Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
    Search for more papers by this author
  • RONALD D. BERGER M.D., Ph.D

    1. Departments of Medicine and Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
    Search for more papers by this author

  • This work was supported by an Established Investigator Award to Dr. Berger from the American Heart Association.

  • Dr. Berger holds a patent on the technology described in the study.

  • Manuscript received 28 March 2007; Revised manuscript received 8 June 2007; Accepted for publication 12 June 2007.

Address for correspondence: Ronald Berger, M.D., Ph.D., The Johns Hopkins University School of Medicine, 600 N. Wolfe Street/Carnegie 592, Baltimore, MD 21287-0409. Fax: 410-502-4854; E-mail: rberger@jhmi.edu

Abstract

Background: Implantable cardioverter defibrillators (ICDs) save lives, but the defibrillation shocks delivered by these devices produce substantial pain, presumably due to skeletal muscle activation. In this study, we tested an electrode system composed of epicardial panels designed to shield skeletal muscles from internal defibrillation, but allow penetration of an external electric field to enable external defibrillation when required.

Methods and Results: Eleven adult mongrel dogs were studied under general anesthesia. Internal defibrillation threshold (DFT) and shock-induced skeletal muscle force at various biphasic shock strengths were compared between two electrode configurations: (1) a transvenous coil placed in the right ventricle (RV) as cathode and a dummy can placed subcutaneously in the left infraclavicular fossa as anode (control configuration) and (2) RV coil as cathode and the multielectrode epicardial sock with the panels connected together as anode (sock-connected). External DFT was also tested with these electrode configurations, as well as with the epicardial sock present, but with panels disconnected from each other (sock-disconnected). Internal DFT was higher with sock-connected than control (24 ± 7 J vs. 16 ± 6 J, P < 0.02), but muscle contraction force at DFT was greatly reduced (1.3 ± 1.3 kg vs. 10.6 ± 2.2 kg, P < 0.0001). External defibrillation was never successful, even at 360 J, with sock-connected, while always possible with sock-disconnected.

Conclusion: Internal defibrillation with greatly reduced skeletal muscle stimulation can be achieved using a novel electrode system that also preserves the ability to externally defibrillate when required. This system may provide a means for painless ICD therapy.

Ancillary