PMID: 9662149Jul 14, 1998Paper

A model study of intramural dispersion of action potential duration in the canine pulmonary conus

Annals of Biomedical Engineering
A W Cates, A E Pollard

Abstract

Regional gradients of action potential duration (APD) due to electrophysiological differences between endocardial, midmyocardial, and epicardial myocytes may exist across the ventricular wall. In addition, activation sequence-induced gradients of APD may occur if intramural fiber rotation accelerates or decelerates the depolarization wave front. To investigate relative contributions of regional and activation sequence-induced gradients to intramural APD dispersion, we simulated action potential propagation in two-dimensional models with idealized geometries representing the canine pulmonary conus. Ionic currents for endocardial myocytes were described using the Luo-Rudy membrane equations. Modifications to I(Ks) approximated action potentials of epicardial and midmyocardial cells. Spatial coupling was modeled with a bidomain representation of tissue structure that included unequal anisotropic conductivity ratios. Activation sequence-induced gradients reached 69 ms cm(-1) during a nonuniform activation sequence where the change in orientation between endocardial and epicardial fibers accelerated the depolarization wave front. Regional gradients reached 133 ms cm(-1) at the boundary between endocardial and midmyocardial cells. Wh...Continue Reading

Citations

Sep 30, 2005·IEEE Transactions on Bio-medical Engineering·Ingrid Schafferhofer-SteltzerAndrew E Pollard
Jul 31, 2004·American Journal of Physiology. Heart and Circulatory Physiology·Andrew E PollardRoger C Barr
May 3, 2005·American Journal of Physiology. Heart and Circulatory Physiology·Steven PoelzingDavid S Rosenbaum
Aug 21, 2007·American Journal of Physiology. Heart and Circulatory Physiology·P Colli FranzoneB Taccardi
Nov 16, 2001·American Journal of Physiology. Heart and Circulatory Physiology·K J Sampson, C S Henriquez

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