Anti-Tachycardia Pacing Simulation in the Human Heart Left Ventricle Using the Luo–Rudy Model

Low-energy pacing is a modern way of treatment dangerous heart rhythm disturbances such as paroxysmal tachy-cardia and fibrillation. The pacing is applied directly to the heart muscle from a small implanted device. The arrhythmias and the treatment can be simulated using reaction-diffusion models and a spatial heart model. One of the most essential outputs of such simulations is the pacing periods with which the treatment succeeds. The present work examines the Luo-Rudy I cell-level model in which the spiral wave meanders and the cycle lengths vary. We compare results of earlier simulations in square with the present computations in a volumetric heart model. Non-uniform spatial meshes are used. The scroll wave stability, filament form and number and pacing results depended on the mesh size and anisotropy ratio. The scroll wave rotated stably and could be superseded in a sparse mesh while it broke up and persisted in a finer mesh. A further analysis of wave propagation in fiber models showed how passing of waves with different periods depended on the mesh size and on the initial pacing period. It turned out that too small as well as too large mesh sizes prevented the high-frequency waves from propagating.