  Radiofrequency catheter ablation (RFCA) is an effective treatment for cardiac
arrhythmias. Although generally safe, it is not completely exempt from the risk
of complications. The great flexibility of computational models can be a major
asset in optimizing interventional strategies, if they can produce sufficiently
precise estimations of the generated lesion for a given ablation protocol. This
requires an accurate description of the catheter tip and the cardiac tissue. In
particular, the deformation of the tissue under the catheter pressure during
the ablation is an important aspect that is overlooked in the existing
literature, that resorts to a sharp insertion of the catheter into an
undeformed geometry. As the lesion size depends on the power dissipated in the
tissue, and the latter depends on the percentage of the electrode surface in
contact with the tissue itself, the sharp insertion geometry has the tendency
to overestimate the lesion obtained, especially when a larger force is applied
to the catheter. In this paper we introduce a full 3D computational model that
takes into account the tissue elasticity, and is able to capture the tissue
deformation and realistic power dissipation in the tissue. Numerical results in
FEniCS-HPC are provided to validate the model against experimental data, and to
compare the lesions obtained with the new model and with the classical ones
featuring a sharp electrode insertion in the tissue.
