Modeling blood flow using constant electrical conductivity of blood predicted lesion depth values within 1 mm of the reference method, offering a suitable alternative to reduce computational complexity.
Modeling blood flow with constant electrical conductivity of blood provides a computationally efficient alternative to modeling full blood motion for predicting RF ablation lesion dimensions.
Our aim was to compare the different methods of modeling the effect of circulating blood flow on the thermal lesion dimensions created by radio frequency (RF) cardiac ablation and on the maximum blood temperature. Computational models were built to study the temperature distributions and lesion dimensions created by a nonirrigated electrode by two RF energy delivery protocols (constant voltage and constant temperature) under high and low blood flow conditions. Four methods of modeling the effect of circulating blood flow on lesion dimensions and temperature distribution were compared. Three of them considered convective coefficients at the electrode-blood and tissue-blood interfaces to model blood flow: 1) without including blood as a part of the domain; 2) constant electrical conductivity of blood; and 3) temperature-dependent electrical conductivity of blood (+2%/°C). Method 4) included blood motion and was considered to be a reference method for comparison purposes. Only Method 4 provided a realistic blood temperature distribution. The other three methods predicted lesion depth values similar to those of the reference method (differences smaller than 1 mm), regardless of ablation mode and blood flow conditions. Considering the aspects of lesion size and maximum temperature reached in blood and tissue, Method 2 seems to be the most suitable alternative to Method 4 in order to reduce the computational complexity. Our findings could have an important implication in future studies of RF cardiac ablation, in particular, in choosing the most suitable method to model the thermal effect of circulating blood.
González‐Suárez et al. (2015) studied RF cardiac ablation. Method 2 (constant electrical conductivity of blood) vs. Method 4 (reference method including blood motion) was evaluated on Lesion depth and maximum temperature. Modeling blood flow using constant electrical conductivity of blood predicted lesion depth values within 1 mm of the reference method, offering a suitable alternative to reduce computational complexity.