Low-dimensional iterated map models have been widely used to study action potential dynamics in isolated cardiac cells. Coupled iterated map models have also been widely used to investigate action potential propagation dynamics in one-dimensional (1D) coupled cardiac cells, however, these models are usually empirical and not carefully validated. In this study, we first developed two coupled ite...

Recently, Spach et al (Circ Res. 1998;83:1144-1164) measured the transmembrane action potential 150 to 200 microm below the tissue surface during longitudinal and transverse propagation. They found that "during longitudinal propagation there was initial slowing of V(m) [action potential] foot that resulted in deviations from a simple exponential. " (p 1144). They attributed this behavior to the...