Early afterdepolarizations in a model of cardiac cells

Using a single Beeler-Reuter patch, we demonstrate that oscillatory responses of transmembrane potential can be simulated in the absence of a constant current stimulus by applying physiologically reasonable parametric variations to the model. Our results indicate that 1) the principal active elements of this periodicity could be limited to the Ca⁺² kinetics, with the K⁺ kinetics playing a passive role, 2) these oscillations are capable of triggering sequences of entrained action potentials in a neighboring cell, and 3) partial K⁺ blockade can facilitate activation in the neighboring cell.