title: Supernormal conduction in cardiac tissue promotes concordant alternans and action potential bunching.
abstract: Supernormal conduction (SNC) in excitable cardiac tissue refers to an increase of pulse (or action potential) velocity with decreasing distance to the preceding pulse. Here we employ a simple ionic model to study the effect of SNC on the propagation of action potentials (APs) and the phenomenology of alternans in excitable cardiac tissue. We use bifurcation analysis and simulations to study attraction between propagating APs caused by SNC that leads to AP pairs and bunching. It is shown that SNC stabilizes concordant alternans in arbitrarily long paced one-dimensional cables. As a consequence, spiral waves in two-dimensional tissue simulations exhibit straight nodal lines for SNC in contrast to spiraling ones in the case of normal conduction.
authors: Departament de Física Aplicada, Universitat Politècnica de Catalunya, E-08028 Barcelona, Spain.
authors: Blas
authors: B
authors: Echebarria
authors: Georg
authors: G
authors: Röder
authors: Harald
authors: H
authors: Engel
authors: Jörn
authors: J
authors: Davidsen
authors: Markus
authors: M
authors: Bär