FIG. 3.

Factors contributing to continuous model cycle length error. (a) In the absence of fibrosis, both the discrete (left panel) and continuous (not shown) models exhibit a hypotrochoid-like spiral wave tip trajectory. In the presence of fibrosis, the discrete mode (center panel) transits from functional to anatomical re-entry with a long, linear tip trajectory, while the equivalent continuous model (right panel) continues to exhibit hypotrochoid-like tip trajectory, albeit significantly flattened due to slowed transverse conduction. Note that all figures show only a part of the domain. Scale bar = 2.5 mm. (b) Restitution behavior during longitudinal pacing is nearly equivalent in the discrete (solid) and homogenous continuous (dashed) models, both in the presence and absence of fibrosis. In the transverse direction, the continuous model restitution curve closely matches the discrete model in non-fibrotic tissues, with slight deviation (up to 14.0%) at intervals below 100 ms. In contrast, in fibrotic tissues, the continuous model exhibits significantly faster conduction (up to 43.4% faster) at intervals below 180 ms.