Effect of skin electrode location on radiofrequency ablation lesions: An in vivo and a three-dimensional finite element study

Skin Electrode Location Affects RF Ablation Lesions. introduction: Objectiv es: To assess the effect of skin electrode location on radiofrequency (RF) ablation lesion dimensions and energy requirements, Background: Little is k nown about the effects of skin electrode location on RF ablation lesion dim ensions and efficiency. Methods and Results: Temperature-controlled ablation at 60 degrees C for 60 seconds was performed in six sheep. Paired lesions were created in the lat eral, anterior, posterior, and septal walls of both the ventricles, For gro up 1 lesions, the skin electrode was positioned directly opposite the cathe ter tip (optimal), For group 2 lesions, we used either the standard posteri or location or an anterior location if the posterior skin electrode locatio n was used for group 1, Group 1 lesions were 5.8 +/- 0.8 mm deep and 9.3 +/ - 1.9 mm wide, compared with 4.6 +/- 1.0 mm deep and 7.7 +/- 1.9 mm wide gr oup 2 lesions (P less than or equal to 0.001), Group 1 lesion dimensions al so had less variability, A finite element model was used to simulate temper ature-controlled ablation and to study the effect of skin electrode locatio ns on lesion dimensions, ablation efficiency, and blood heating, The optima l location was 1.6 times more efficient, and the volume of blood heated to greater than or equal to 90 degrees C was 0.005 mm(3) for optimal versus 2. 2 mm(3) for the nonoptimal location, Conclusion: Optimal skin electrode placement: (1) creates deeper and larger lesions; (2) reduces lesion size variability; and (3) decreases blood heat ing.