Dimensional comparison of the sawtooth pattern in transmembrane potential

The authors study the steady-state response to an outer electric field in a 3D cardiac model with periodic structure. The applied field generates a sawtooth pattern in the transmembrane potential similar to the one found in 1D simulations. In higher dimensions however, the cell geometry, the relation between the conductivity of the intracellular matrix and the gap junctional resistance, and the 3D relation between the cells all determine the magnitude and the shape of the sawtooth. Altering the way in which the cells are aligned, or smearing out the gap junctions without altering their total resistance, can, each change the magnitude of the sawtooth by 25% and alter its shape significantly.<>