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Discrete Dynamics in Nature and Society
Volume 2013 (2013), Article ID 687472, 14 pages
http://dx.doi.org/10.1155/2013/687472
Research Article

Effects of Calcium-Channel Noise on Dynamics of Excitation-Contraction Coupling in Paced Cardiac Cells

Department of Mathematics, MOE-LSC, Shanghai Jiao Tong University, Shanghai 200240, China

Received 21 June 2013; Revised 19 August 2013; Accepted 22 August 2013

Academic Editor: Daniele Fournier-Prunaret

Copyright © 2013 Jiying Ma and Dongmei Xiao. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We study a simple discrete model with the impact of calcium-channel noise on the beat-to-beat dynamics of cardiac cells. The effects of the noise are assessed by bifurcation analysis and power spectrum analysis, respectively. It is shown that this model can undergo period-doubling bifurcation and Hopf bifurcation if there are not random perturbations. Under random perturbations, the period-doubling bifurcations of the model can be observed, and the invariant curve from Hopf bifurcation is perturbed to an annulus on the plane and then becomes a totally disordered and randomly scattered region. By the power spectrum analysis, we find that the existence of high-frequency peak in the power spectra links to the period-doubling orbits, while the existence of low-frequency peak corresponds to quasiperiodic orbit.