  In this work we address the issue of validating the monodomain equation used
in combination with the Bueno-Orovio ionic model for the prediction of the
activation times in cardiac electro-physiology of the left ventricle. To this
aim, we consider our patients who suffered from Left Bundle Branch Block
(LBBB). We use activation maps performed at the septum as input data for the
model and maps at the epicardial veins for the validation. In particular, a
first set (half) of the latter are used to estimate the conductivities of the
patient and a second set (the remaining half) to compute the errors of the
numerical simulations. We find an excellent agreement between measures and
numerical results. Our validated computational tool could be used to accurately
predict activation times at the epicardial veins with a short mapping, i.e. by
using only a part (the most proximal) of the standard acquisition points, thus
reducing the invasive procedure and exposure to radiation.
