An analytical three-resistor model for radiofrequency cardiac ablation estimated impedance values of approximately 75 ohms for the active electrode, 20 ohms for the dispersive electrode, and 15±10 ohms for the body.
A simple three-resistor lumped-element model can effectively estimate electrical impedance components during radiofrequency cardiac ablation, aiding in the understanding of electrical and thermal behavior during the procedure.
The electrical impedance measured during radiofrequency cardiac ablation (RFCA) is widely used in clinical studies to predict the heating evolution and hence the success of the procedure. We hypothesized that a model based on three resistors in series can mimic the total electrical impedance measured during RFCA. The three resistors or impedances are given by: impedance associated with the tissue around the active electrode (myocardium and circulating blood) (Z-A), that associated with the tissue around the dispersive electrode (Z-DE) and that associated with the rest of the body (Z-B). Our objective was to quantify the values associated with these three impedance types by an analytical method, after which the values obtained would be compared to those estimated from clinical data from previous studies. The results suggest that an RFCA using a 7 Fr 4-mm electrode would give a Z-A of around 75 ohms, a Z-DE around 20 ohms, and Z-B would be 15±10 ohms (for body surface area variations between 1. 5 and 2. 5 m²). Finally, adaptations of the proposed model were used to explain the results of previous clinical studies using a different electrode arrangement, such as in bipolar ablation of the ventricular septum.
Berjano et al. (Tue,) conducted a other in Radiofrequency Cardiac Ablation. Three-resistor lumped element electrical model was evaluated on Estimation of impedance values (ZA, ZDE, ZB). An analytical three-resistor model for radiofrequency cardiac ablation estimated impedance values of approximately 75 ohms for the active electrode, 20 ohms for the dispersive electrode, and 15±10 ohms for the body.