Shortening of Cardiac Action Potential Duration Near an Insulating Boundary

John W. Cain, University of Richmond
David G. Schaeffer


It is known, from both experiments and simulations, that cardiac action potentials are shortened near a nonconducting boundary. In the present paper, this effect is studied in a simple, two-current ionic model, with propagation restricted to a one-dimensional fiber. An asymptotic approximation for the dependence of action potential duration on distance to the boundary is derived. This estimate agrees well with simulations.