FIG. 5.

Hybrid models improve continuous model accuracy. The introduction of discrete heterogeneities (in the form of decoupling septa) in the continuous model allows for accurately replicating discrete model behavior. (a) The degree of fibrosis in the hybrid model was tuned to match discrete model cycle length. For each level of fibrosis, tissue conductivities were first adjusted to match discrete planar conduction velocities. The hybrid model with 50% fibrosis was selected for further use. (b) The hybrid model maintains 18× computational efficiency of the continuous model when each is run with equal computing resources. (c) The selected hybrid model produces electrograms that qualitatively display complexity and fractionation similar to the discrete model. (d) The tip trajectory in the hybrid model is similar to that of the discrete model with a long and narrow path. Note that this panel shows only a part of the domain. Scale bar = 2.5 mm. (e) The transverse restitution behavior of the hybrid tissue (dotted) remains the same as that of the continuous model (dashed) rather than that of the discrete model (solid).