A fast model for simulating reentry in three dimensions with fiber rotation

Transmural rotation of cardiac fibers may have a large influence on reentry in the heart. However, modeling reentry is computationally challenging since the tissue modeled must be large enough to sustain reentry and this leads to a system of with millions of variables. A method is presented which decreases computation time due to its use of a discrete cable model which allows for system order reduction, and because it tracks the activation wavefront and only integrates the neighborhood of the front with a small time step. Simulations of approximately 1.8×10⁶ cells in a block measuring 2×4×0.29 cm were possible in a reasonable amount of time. The effect on speed and accuracy of model parameters is discussed. It is also demonstrated that the method lends itself well to parallel computation. The effect of fiber rotation can be clearly seen during reentry