[@Bishop-etal-2010; @Bishop-etal-2011; @Bishop-Plank-2012; @Fukumoto-etal-2016], and has been studied in simplified mathematical and computer models [@Fenton-Karma-1998; @Pertsov-etal-PRL2000; @Wellner-etal-PNAS2002; @RodriguezEasonTrayanova-2006; @Dierckx-etal-PRE2013]. [ The anisotropic discontinuities in the heart muscle have been commonly seen as a substrate for rise of cardiac re-entry due to the abrupt change in conduction velocity and wavefront curvature. On the other hand, [extensive mapping of cardiac myocyte orientation in mammalian hearts has shown that the transmural fiber arrangement, including the range of transmural change in fiber angle in ventricular wall, was consistent within a species, and varied between species[@Hunter-etal-CompBiolOfHeart p. 173]. ]{} So that changes in anisotropy seen in healthy hearts can facilitate initiation of arryhthmias. ]{}

The recent advance in DT-MRI technology and High Performance Computing (HPC) allows the obtained DT-MRI data sets with the detailed heart anatomy and myofiber structure to be directly incorporated into the anatomically realistic computer simulations [@bbx-2017-PONE], so that the anisotropy of the tissue in the *in-silico* model can be switched on and off to allow for comparison between the anatomically realistic isotropic and anisotropic conduction in order to see specific anatomy effects as well as the interplay between the anisotropy and anatomy of an individual heart.

In this paper, we present 