WIAS Preprint No. 2045, (2014)

Cardiac contraction induces discordant alternans and localized block



Authors

  • Radszuweit, Markus
  • Alvarez-Lacalle, Enrique
  • Bär, Markus
  • Echebarria, Blas

2010 Mathematics Subject Classification

  • 92B05 65M06

2008 Physics and Astronomy Classification Scheme

  • 87.19.Hh, 87.19.R-, 05.45.-a, 89.75.-k

Keywords

  • nonlinear dynamics, cardiac alternans, amplitude equations

Abstract

In this paper we use a simplified model of cardiac excitation-contraction coupling to study the effect of tissue deformation on the dynamics of alternans, i.e. alternations in the duration of the cardiac action potential, that occur at fast pacing rates and are known to be pro-arrhythmic. We show that small stretch-activated currents can produce large effects and cause a transition from in-phase to off-phase alternations (i.e. from concordant to discordant alternans) and to conduction blocks. We demonstrate numerically and analytically that this effect is the result of a generic change in the slope of the conduction velocity restitution curve due to electromechanical coupling. Thus, excitation-contraction coupling can potentially play a relevant role in the transition to reentry and fibrillation.

Appeared in

  • Phys. Rev. E (3), 91 (4.2.2015) pp. 022703.

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