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Comparative Study
. 2005 Feb;71(2 Pt 1):021903.
doi: 10.1103/PhysRevE.71.021903. Epub 2005 Feb 8.

Coupled dynamics of voltage and calcium in paced cardiac cells

Yohannes Shiferaw  1 , Daisuke Sato, Alain Karma
Affiliations
Comparative Study

Coupled dynamics of voltage and calcium in paced cardiac cells

Yohannes Shiferaw et al. Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Feb.

Abstract

We investigate numerically and analytically the coupled dynamics of transmembrane voltage and intracellular calcium cycling in paced cardiac cells using a detailed physiological model, and its reduction to a three-dimensional discrete map. The results provide a theoretical framework to interpret various experimentally observed modes of instability ranging from electromechanically concordant and discordant alternans to quasiperiodic oscillations of voltage and calcium.

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Figures

FIG. 1
FIG. 1
Illustration of currents that control the dynamics of voltage and intracellular calcium cycling.
FIG. 2
FIG. 2
Illustration of the effect of an increase in the magnitude of the calcium transient, which can prolong or shorten the APD for (a) positive and (b) negative coupling, respectively. The sign of the coupling depends on the relative contributions of ICa and INaCa to the APD. The solid or dashed lines correspond to the same beat.
FIG. 3
FIG. 3
Stability boundaries in the ionic model for positive (dashed line; γ = 0.7) and negative (solid line; γ = 1.5) coupling. T = 300 ms. Examples of steady-state dynamics close to the stability boundaries are illustrated by plots of peak calcium concentration (cipeak) vs APD for a few labeled points. Higher order periodicities and irregular dynamics are observed further away from these boundaries.
FIG. 4
FIG. 4
Definition of map variables.
FIG. 5
FIG. 5
Stability boundaries from the map analysis for positive coupling C = 0.1 with concordant alternans along the dashed line, and negative coupling C = −0.1 (solid line), with concordant alternans, discordant alternans, and quasiperiodicity along the segments a–b, c–d, and b–c, respectively.
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References

    1. Karma A. Chaos. 1994;4:461. - PubMed
    1. Garfinkel A, et al. Proc. Natl. Acad. Sci. U.S.A. 2000;97:6061. - PMC - PubMed
    1. Courtemanche M, Glass L, Keener JP. Phys. Rev. Lett. 1993;70:2182. - PubMed
    2. Echebarria B, Karma A. ibid. 2002;88:208101. - PubMed
    1. Nolasco JB, Dahlen RW. J. Appl. Physiol. 1968;25:191. - PubMed
    2. Guevara MR, et al. Proceedings of the 11th Computers in Cardiology Conference; IEEE Computer Society; Los Angeles. 1984. p. 167.
    1. Hall GM, Bahar S, Gauthier DJ. Phys. Rev. Lett. 1999;82:2995.
    2. Hall GM, Gauthier DJ. ibid. 2002;88:198102. - PubMed

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