Directional characteristics of action potential propagation in cardiac muscle. A model study
- PMID: 1860179
- DOI: 10.1161/01.res.69.2.378
Directional characteristics of action potential propagation in cardiac muscle. A model study
Abstract
Propagation of an elliptic excitation wave front was studied in a two-dimensional model of a thin sheet of cardiac muscle. The sheet model of 2.5 x 10 mm consisted of a set of 100 parallel cables coupled through a regular array of identical transverse resistors. The membrane dynamics was represented by a modified Beeler-Reuter model. We defined the charging factor (CF) to represent by a single number the proportion of input current used to charge the membrane locally below threshold and showed that CF is inversely correlated with the time constant of the foot of the action potential (tau foot) during propagation on a cable. A safety factor of propagation (SF) was also defined for the upstroke of the action potential, with SF directly correlated with the maximum rate of depolarization (Vmax) and, for cablelike propagation, with propagation velocity. Propagation along the principal longitudinal axis of the elliptic wave front is cablelike but, in comparison with a flat wave front, transverse current flow provides a drag effect that somewhat reduces the propagation velocity, Vmax, SF, and CF. With a longitudinal-to-transverse velocity ratio of 3:1 or more, the wave front propagating along the principal transverse axis is essentially flat and is characterized by multiple collisions between successive pairs of input junctions on a given cable; Vmax, SF, and CF are larger than for longitudinal propagation, but CF is no longer correlated with tau foot. There are transient increases in propagation velocity and Vmax with distance from the stimulation site along both principal axes until stablized values are achieved, and a similar transient decrease in tau foot. Away from the principal axes, the action potential characteristics change progressively along the elliptic wave front.(ABSTRACT TRUNCATED AT 250 WORDS)
Similar articles
-
Structural complexity effects on transverse propagation in a two-dimensional model of myocardium.IEEE Trans Biomed Eng. 1991 Oct;38(10):997-1009. doi: 10.1109/10.88445. IEEE Trans Biomed Eng. 1991. PMID: 1761300
-
Propagating depolarization in anisotropic human and canine cardiac muscle: apparent directional differences in membrane capacitance. A simplified model for selective directional effects of modifying the sodium conductance on Vmax, tau foot, and the propagation safety factor.Circ Res. 1987 Feb;60(2):206-19. doi: 10.1161/01.res.60.2.206. Circ Res. 1987. PMID: 2436826
-
Reconstruction of propagated electrical activity with a two-dimensional model of anisotropic heart muscle.Circ Res. 1986 Apr;58(4):461-75. doi: 10.1161/01.res.58.4.461. Circ Res. 1986. PMID: 3698214
-
Anisotropic activation spread in heart cell monolayers assessed by high-resolution optical mapping. Role of tissue discontinuities.Circ Res. 1996 Jul;79(1):115-27. doi: 10.1161/01.res.79.1.115. Circ Res. 1996. PMID: 8925559 Review.
-
Mechanisms for nonuniform propagation along excitable cables.Ann N Y Acad Sci. 1990;591:51-61. doi: 10.1111/j.1749-6632.1990.tb15080.x. Ann N Y Acad Sci. 1990. PMID: 2197933 Review.
Cited by
-
Coupling between cardiac cells-An important determinant of electrical impulse propagation and arrhythmogenesis.Biophys Rev (Melville). 2021 Sep;2(3):031301. doi: 10.1063/5.0050192. Epub 2021 Jul 13. Biophys Rev (Melville). 2021. PMID: 34296210 Free PMC article. Review.
-
Sensitivity analysis of an electrophysiology model for the left ventricle.J R Soc Interface. 2020 Oct;17(171):20200532. doi: 10.1098/rsif.2020.0532. Epub 2020 Oct 28. J R Soc Interface. 2020. PMID: 33109017 Free PMC article.
-
New insights on the cardiac safety factor: Unraveling the relationship between conduction velocity and robustness of propagation.J Mol Cell Cardiol. 2019 Mar;128:117-128. doi: 10.1016/j.yjmcc.2019.01.010. Epub 2019 Jan 22. J Mol Cell Cardiol. 2019. PMID: 30677394 Free PMC article.
-
Changes in Myocardial Composition and Conduction Properties in Rat Heart Failure Model Induced by Chronic Volume Overload.Front Physiol. 2016 Aug 25;7:367. doi: 10.3389/fphys.2016.00367. eCollection 2016. Front Physiol. 2016. PMID: 27610087 Free PMC article.
-
Ventricular anti-arrhythmic effects of heptanol in hypokalaemic, Langendorff-perfused mouse hearts.Biomed Rep. 2016 Mar;4(3):313-324. doi: 10.3892/br.2016.577. Epub 2016 Jan 21. Biomed Rep. 2016. PMID: 26998268 Free PMC article.
Publication types
MeSH terms
LinkOut - more resources
Full Text Sources
Miscellaneous