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09:24
Multiparametric Optical Mapping of the Langendorff-perfused Rabbit Heart
Published on: September 13, 2011
Virtual electrode effects in transvenous defibrillation-modulation by structure and interface: evidence from bidomain
E Entcheva1, J Eason, I R Efimov
1Joint Department of Biomedical Engineering, The University of Memphis and University of Tennessee, USA.
Journal of Cardiovascular Electrophysiology
|October 24, 1998
Summary
Virtual electrode effects (VEE) occur during implantable cardioverter defibrillator (ICD) shocks, impacting defibrillation outcomes. These effects depend on cardiac tissue properties and interface conditions, influencing transmembrane potential changes.
Area of Science:
- Biophysics
- Cardiovascular Physiology
- Computational Biology
Background:
- Investigating transmembrane potential changes during implantable cardioverter defibrillator (ICD) shocks.
- Testing hypotheses on the presence and characteristics of virtual electrode effects (VEE) during ICD shocks.
Purpose of the Study:
- To understand virtual electrode effects (VEE) in defibrillation conditions.
- To numerically and experimentally test anisotropy-dependent VEE in myocardium and surface VEE under specific conditions.
Main Methods:
- Combined numerical modeling and experimental optical mapping on Langendorff-perfused rabbit hearts.
- Simulated defibrillation shocks using an ellipsoidal bidomain heart model with transmural fiber rotation.
- Applied monophasic shocks via specific electrode configurations in both modeling and experiments.
Main Results:
- Numerical simulations revealed VEE in a significant portion of the myocardium with unequal anisotropy ratios.
- Experimental optical mapping confirmed VEE presence and characteristics.
- Variations in interface conditions led to statistically significant differences in predicted and observed epicardial polarization patterns.
Conclusions:
- Virtual electrode effects (VEE) are present during transvenous defibrillation.
- VEE are influenced by cardiac tissue characteristics and interface conditions.
- The significant size of VEE suggests a notable contribution to defibrillation success.
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