Impact of Catheter Orientation on Cardiac Radiofrequency Ablation

Radiofrequency ablation is a typical treatment for severe cases of cardiac arrhythmias. A catheter, inserted from the patient’s groin, delivers current at frequencies of 450–500 kHz to the arrhythmogenic area, inflicting thermal damage. The electrical current delivered to the tissue depends (among others) on the tip shape and the catheter orientation. A modified Penne’s bioheat equation with an electric source and cooling blood convection is the standard choice for RFA models. The incompressible Navier-Stokes equation describes the interaction of the blood flow and the irrigated saline. The cardiac tissue is a nonlinear orthotropic hyperelastic material and the Hertz-Signorini-Moreau contact boundary conditions model the frictionless interaction of the electrode with the cardiac tissue. In this work, we consider a spherical electrode tip shape and different orientation angles (from perpendicular up to 60 \(^{\circ }\) from the vertical position). We perform a virtual ablation for a standard protocol of power 30 W for a duration of 30 s on a simulated porcine cardiac slab. We compare the contact surface of the electrode with the tissue for the different orientations and the characteristics of the generated lesions.