Berlin 2012 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 19: Nonlinear Dynamics of the Heart: Contributed talks to focus session

DY 19.3: Talk

Wednesday, March 28, 2012, 15:30–15:45, MA 001

Cardiac contraction and mechano-electric feedback promotes discordant alternans — Enric Álvarez-Lacalle¹, Markus Bär², Blas Echebarria¹, and •Markus Radszuweit² — ¹Dept. Física Aplicada, Universitat Politècnica de Catalunya, 44-50 Av. Dr. Maranón, 08028 Barcelona, Spain — ²Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany

By means of numerical simulations of the Fenton-Karma model with electromechanical coupling we investigate the effect of contraction on cardiac alternans. The study is confined to action potential propagation along a quasi-one-dimensional cable where the mechanoelectrical feedback on the membrane voltage results from stretch-activated currents. The electromechanical coupling is approximated by a global coupling term following Alvarez-Lacalle and Echebarria, Phys. Rev. E 79, 031921 (2009). Discordant alternans is often a precursor for life-threatening arrhythmias like ventricular fibrillation and is often caused by a steep slope of conduction velocity (CV) restitution curve. Here, we show that contraction switches the dynamics from concordant to discordant alternans even when the CV restitution curve is practically flat at the onset of alternans. This result demonstrates the need to include the mechanics of the tissue in models of electrical propagation.