Evaluation of Activation Times in Ventricular Model with Realistic Geometry and Conduction System

The goal of the article was to design a model of ventricles with a realistic patient geometry and with a proper representation of the conduction system of ventricles that enables to reach the total activation time of the whole ventricles in the physiological range of about 80 to 120 ms. Electrical activation was started in one region or in nine starting regions. The conduction system (branches and Purkinje fibers) was modeled as an endocardial layer with higher conductivity and a set of nine starting regions representing the earliest activated areas. The monodomain model of electrical activation propagation with the local tissue properties defined by modified FitzHugh-Nagumo equations was numerically solved in Comsol Multiphysics environment. The total activation time of the whole ventricles was evaluated for all models. Pathological total activation times of the whole ventricles higher than 120 ms were obtained for models with activation starting only in one region (ectopic beats). Realistic total activation time was obtained for model incorporating an endocardial conducting layer with nine starting regions representing the conduction system.