Biophysical Journal 71: 2427-2439 (1996)
© 1996 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wu, J Articles by Kootsey, J M Search for Related Content PubMed PubMed Citation Articles by Wu, J Articles by Kootsey, J M

A quasi-one-dimensional theory for anisotropic propagation of excitation in cardiac muscle.

Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710, USA. jiashin@dendrite.phy.vanderbilt.edu

ABSTRACT

It has been shown that propagation of excitation in cardiac muscle is anisotropic. Compared to propagation at right angles to the long axes of the fibers, propagation along the long axis is faster, the extracellular action potential (AP) is larger in amplitude, and the intracellular AP has a lower maximum rate of depolarization, a larger time constant of the foot, and a lower peak amplitude. These observations are contrary to the predictions of classical one-dimensional (1-D) cable theory and, thus far, no satisfactory theory for them has been reported. As an alternative description of propagation in cardiac muscle, this study provides a quasi-1-D theory that includes a simplified description of the effects of action currents in extracellular space as well as resistive coupling between surface and deeper fibers in cardiac muscle. In terms of classical 1-D theory, this quasi-1-D theory reveals that the anisotropies in the wave form of the AP arise from modifications in the effective membrane ionic current and capacitance. The theory also shows that it is propagation in the longitudinal, not in the transverse direction that deviates from classical 1-D cable theory.

This article has been cited by other articles:

				B. J. Roth Influence of a Perfusing Bath on the Foot of the Cardiac Action Potential Circ. Res., February 4, 2000; 86 (2): e19 - e22. [Abstract] [Full Text] [PDF]

				M. S. Spach and R. C. Barr Effects of Cardiac Microstructure on Propagating Electrical Waveforms Circ. Res., February 4, 2000; 86 (2): e23 - e28. [Abstract] [Full Text] [PDF]

				M. S. Spach, J. F. Heidlage, P. C. Dolber, and R. C. Barr Extracellular Discontinuities in Cardiac Muscle : Evidence for Capillary Effects on the Action Potential Foot Circ. Res., November 30, 1998; 83(11): 1144 - 1164. [Abstract] [Full Text] [PDF]

				X. Zhou, S. B. Knisley, W. M. Smith, D. Rollins, A. E. Pollard, and R. E. Ideker Spatial Changes in the Transmembrane Potential During Extracellular Electric Stimulation Circ. Res., November 16, 1998; 83(10): 1003 - 1014. [Abstract] [Full Text] [PDF]