How does radiofrequency ablation efficacy depend on the stiffness of the cardiac tissue? Insights from a computational model

Objective. Radiofrequency catheter ablation (RFCA) is an effective treatment for the elimination of cardiac arrhythmias, however it is not exempt from complications that can risk the patients’ life. The efficacy of the RFCA depends on several factors and uncertainties during the treatment process. In this paper, we explore the effect of the cardiac tissue stiffness in RFCA. Methods. We use our previously developed RFCA computational model that accounts for the tissue elasticity. The tissue stiffness is described by the Young’s modulus of elasticity. Results. Our numerical simulations provide insights on the efficacy of the RFCA, by measuring the lesion dimensions over a wide range of values of the modulus of elasticity that appear during the cardiac cycle and for different cardiac conditions, using a fixed ablation protocol, commonly used in clinical practice. Conclusion. The stiffness of the cardiac wall affects the power dissipated in the tissue and, as a consequence, has a marked effect on the dimensions of the generated lesion. The heart wall elasticity changes due the cardiac cycle can affect the resulting lesion and can lead to potentially dangerous complications. Pathological conditions can stiffen the cardiac wall, thus reducing the size of the resulting lesion and potentially leading to insufficient treatment. Significance. A relation of the lesion size dimensions for different tissue stiffness and contact force is presented and correlated to different pathological conditions of the heart, showing the direct relation of the tissue stiffness with the efficacy of the RFCA treatment

Effect of Tissue Elasticity in Cardiac Radiofrequency Catheter Ablation Models

Radiofrequency catheter ablation (RFCA) is an effective treatment for different types of cardiac arrhythmias. However, major complications can occur, including thrombus formation and steam pops. We present a full 3D mathematical model for the radiofrequency ablation process that uses an open-irrigated catheter and accounts for the tissue deformation, an aspect overlooked by the existing literature. An axisymmetric Boussinesq solution for spherical punch is used to model the deformation of the tissue due to the pressure of the catheter tip at the tissue-catheter contact point. We compare the effect of the tissue deformation in the RFCA model against the use of a standard sharp insertion of the catheter in the tissue that other state-of- the-art RFCA computational models use.La Caixa 2016 PhD grant to M.L