Direction Des Bibliothèques the Dynamics of Sustained Reentry in a Loop Model with Discrete Gap Junction Resistance Par

In a normal heartbeat, electrical activation starts from the SA node and propagates to both atria. It travels successively through the AV node, the His Bundle and finally the Purkinje fibers that distribute the excitation and contract ventricles. The electrical activation is formed by the unequal ionic distribution on both sides of the sarcoplasmic membrane, producing a difference of potential between the intra and extracellular media. The electrical properties of the ventricular cardiac myocytes are described by the different mathematical models. The Hodgkin-Huxley model and Beeler-Reuter model use the ordinary differential equation to simulate membrane potential as a time-dependent function. The bifurcation phenomena of action potential duration and diastolic interva.l are simulated, which are proved by the finite difference model. The action potential propagates in cardiac tissue. The low-dimensional model was employed. In the one-dimensional model, since cardiac tissue is regarded as the uniform continuous cable, bifurcation phenomena are simulated, and these results are proven by the integral delay model. The other model is that the gap junction resistance exists between cells. The propagation delay is shown between cells. The action potential propagates in the one-dimensional ring with the gap junction resistance, shown to be the most interesting in recent research. The purpose of our study is to investigate the effect of gap junction resistance on the characteristics of reentry in a one-dimensional ring of model cardiac tissue. Tachyarrhythmia is commonly induced by reentry. Cardiac reentry corresponds to the self-sustained propagation of an activation front around a functiona.l or anatomica.l obstacle. Propagation around a one-dimensional ring is the simplest model of reentry. Previous work on a uniform continuous I-D ring model, with membrane properties represented by an ionic model, has shown that reentry was still sustained but quasiperiodic, below a critical length Lcrit , and that it was blocked for rings shorter than a minimum length Lmin. The transition from periodic to