Effect of Fiber Direction and Ionic Heterogeneities in Atrial Driver Location

Digital twins are a tool used to simulate patients with atrial fibrillation (AF).However, the level of detail needed to use this tool clinically is still unknown.This paper evaluates the effect of the inclusion of two important characteristics of atrial substrate like fiber direction (FD) and ionic heterogeneities (IH).In this work, a bi-atrial 3D anatomical model was used to evaluate the effect of FD and IH, which were defined for each type of tissue.Multiple simulations were launched using variations of two stimulation protocols to generate arrhythmic patterns and measure the number of reentrant cases as well as the behavior of the reentries in presence or absence of FD and IH.Inclusion of FD had a notorious effect reaching 51% of arrhythmic cases, while in its absence the percentage fell to 24%.IH did not play such an important role considering the number of arrhythmic cases, but its influence was in the type, since the number of potential locations maintaining AF increased with the addition of IH.Adding FD has a great effect on the arrhythmic behavior of biophysical simulations.Inclusion of IH, despite being less important considering quantity in comparison to FD, has a great influence on the type and region.