Electroporation and shock-induced transmembrane potential in a cardiac fiber during defibrillation strength shocks.

Published

Journal Article

Experimental studies have shown that the magnitude of the shock-induced transmembrane potential (Vm) saturates with increasing electric field strength. This study uses a mathematical model to investigate the effects of electroporation and membrane kinetics on Vm in a cardiac fiber. The model consists of the core conductor equation for a one-dimensional fiber, where excitability is represented by the Luo-Rudy dynamic model (1994-1995) and electroporation is described by a membrane conductance that increases exponentially with Vm squared. For shocks delivered during the plateau of an action potential, the model reproduces the experimentally observed saturation of Vm with a root mean square error of 4.27% and a correlation coefficient of 0.9992. For shocks delivered during diastole, the saturation of Vm is qualitatively reproduced even when the sodium and calcium channels are inactivated. Quantitative replication of the response to diastolic shocks is hindered by the choice of electroporation parameters (optimized for shocks delivered during the plateau) and differences in the membrane kinetics between model and experiment. The complex behavior of Vm during large shocks is due to a combination of electroporation, electrotonus, propagation, and active membrane kinetics. The modeling results imply that the experimentally observed saturation of Vm is due to electroporation of the lipid bilayer.

Full Text

Duke Authors

Cited Authors

  • DeBruin, KA; Krassowska, W

Published Date

  • July 1998

Published In

Volume / Issue

  • 26 / 4

Start / End Page

  • 584 - 596

PubMed ID

  • 9662151

Pubmed Central ID

  • 9662151

Electronic International Standard Serial Number (EISSN)

  • 1573-9686

International Standard Serial Number (ISSN)

  • 0090-6964

Digital Object Identifier (DOI)

  • 10.1114/1.101

Language

  • eng