Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Virtual electrode-induced phase singularity: a basic mechanism of defibrillation failure

I R Efimov1, Y Cheng, D R Van Wagoner

  • 1Department of Cardiology, Cleveland Clinic Foundation, Ohio 44195, USA. efimovi@cesmtp.ccf.org

Circulation Research
|May 12, 1998
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Multi-omics integration identifies key upstream regulators of pathomechanisms in hypertrophic cardiomyopathy due to truncating MYBPC3 mutations.

Clinical epigenetics·2021
Same author

β-adrenergic stimulation augments transmural dispersion of repolarization via modulation of delayed rectifier currents I<sub>Ks</sub> and I<sub>Kr</sub> in the human ventricle.

Scientific reports·2017
Same author

Human Organotypic Cultured Cardiac Slices: New Platform For High Throughput Preclinical Human Trials.

Scientific reports·2016
Same author

Technical advances in studying cardiac electrophysiology - Role of rabbit models.

Progress in biophysics and molecular biology·2016
Same author

Arrhythmogenic and metabolic remodelling of failing human heart.

The Journal of physiology·2016
Same author

Structure-function relationship in the sinus and atrioventricular nodes.

Pediatric cardiology·2012

Virtual electrode patterns (VEPs) from defibrillation shocks can cause arrhythmias. Optimal biphasic waveforms avoid VEPs, preventing reentrant arrhythmias and improving implantable cardioverter defibrillator (ICD) therapy.

Area of Science:

  • Cardiovascular Electrophysiology
  • Medical Device Engineering
  • Cardiac Arrhythmia Mechanisms

Background:

  • Implantable cardioverter defibrillators (ICDs) use electric shocks for ventricular fibrillation, but defibrillation mechanisms are unclear.
  • Monophasic shocks create virtual electrode patterns (VEPs), non-uniform polarization linked to defibrillation failure.
  • VEPs may induce arrhythmias by causing repolarization dispersion and reentry.

Purpose of the Study:

  • Investigate if VEPs contribute to defibrillation failure.
  • Determine the role of VEPs in postshock repolarization dispersion and reentry.
  • Identify optimal biphasic shock waveforms to prevent VEP formation and arrhythmias.

Main Methods:

  • Used Langendorff-perfused rabbit hearts and a bipolar ICD lead.

Related Experiment Videos

  • Delivered truncated exponential monophasic and biphasic shocks.
  • Employed high-resolution epicardial fluorescence mapping (256 sites) with voltage-sensitive dye.

    • Main Results:

    • Monophasic and weak biphasic shocks (<20%) created VEPs, leading to arrhythmias.
    • Strong biphasic shocks (>70%) reversed VEP polarity, also causing arrhythmias.
    • Intermediate biphasic shocks (20-70%) prevented VEPs by asymmetric polarization reversal, inhibiting reentry.

    Conclusions:

    • Shock-induced VEPs can reinduce arrhythmias through phase singularity mechanisms.
    • Optimal defibrillation waveforms avoid VEPs by asymmetric polarization effects, thus preventing reentry.
    • Understanding VEPs is crucial for developing safer and more effective ICD therapies.