In standard models of cardiac electrophysiology, including the bidomain and monodomain models, local perturbations can propagate at infinite speed. We address this unrealistic property by developing a hyperbolic bidomain model that is based on a generalization of Ohm's law with a Cattaneo-type model for the fluxes. Further, we obtain a hyperbolic monodomain model in the case that the intracellular and extracellular conductivity tensors have the same anisotropy ratio. In one spatial dimension, the hyperbolic monodomain model is equivalent to a cable model that includes axial inductances, and the relaxation times of the Cattaneo fluxes are strictly related to these inductances. A purely linear analysis shows that the inductances are negligible, but models of cardiac electrophysiology are highly nonlinear, and linear predictions may not capture the fully nonlinear dynamics. In fact, contrary to the linear analysis, we show that for simple nonlinear ionic models, an increase in conduction velocity is obtained for small and moderate values of the relaxation time. A similar behavior is also demonstrated with biophysically detailed ionic models. Using the Fenton-Karma model along with a low-order finite element spatial discretization, we numerically analyze differences between the standard monodomain model and the hyperbolic monodomain model. In a simple benchmark test, we show that the propagation of the action potential is strongly influenced by the alignment of the fibers with respect to the mesh in both the parabolic and hyperbolic models when using relatively coarse spatial discretizations. Accurate predictions of the conduction velocity require computational mesh spacings on the order of a single cardiac cell. We also compare the two formulations in the case of spiral break up and atrial fibrillation in an anatomically detailed model of the left atrium, and [...].
Exponential Adams Bashforth integrators for stiff ODEs, application to cardiac electrophysiology
INRIA Bordeaux, Institut de Mathématiques de Bordeaux, UMR CNRS 5241, Université de Bordeaux（法国国家信息与自动化研究所波尔多中心，波尔多数学研究所）；Université de Pau et des Pays de l’Adour（波尔多大学）；Laboratoire de Mathématiques et de leurs Applications, UMR CNRS 5142, Université de Pau et des Pays de l’Adour（波尔多大学）
Efficient high order schemes for stiff ODEs in cardiac electrophysiology
INRIA Bordeaux Sud Ouest, Université de Bordeaux（法国国家信息与自动化研究所波尔多西南分部，波尔多大学）；Institut de Mathématiques de Bordeaux, UMR CNRS 5241（波尔多数学研究所）；Laboratoire de Mathématiques et de leurs Applications, UMR CNRS 5142, Université de Pau et des Pays de l’Adour（波尔多大学及阿杜尔地区大学数学及其应用实验室）
AutoVARP -- a framework for automated reproducible inducibility testing in computational models of cardiac electrophysiology
Gottfried Schatz Research Center, Division of Medical Physics and Biophysics, Medical University of Graz（格拉茨医科大学医学物理与生物物理学系戈特弗里德·沙茨研究中心）；King's College London（伦敦国王学院）
Novel bidomain partitioned strategies for the simulation of ventricular fibrillation dynamics
School of Mathematics, IISER Thiruvananthapuram（印度国家研究所特瓦纳纳拉帕数学学院）；Interdisciplinary Center for Scientific Computing, Heidelberg University（海德堡大学跨学科科学计算中心）；Center for High-Performance Computing, IISER Thiruvananthapuram（印度国家研究所特瓦纳纳拉帕高性能计算中心）
