Temperature-controlled and constant-power radio-frequency ablation: what affects lesion growth?
Radio-frequency (RF) catheter ablation is the primary interventional therapy for the treatment of many cardiac tachyarrhythmias. Three-dimensional finite element analysis of constant-power (CPRFA) and temperature-controlled RF ablation (TCRFA) of the endocardium is performed. The objectives are to study: 1) the lesion growth with time and 2) the effect of ground electrode location on lesion dimensions and ablation efficiency. The results indicate that: a) for TCRFA: i) lesion growth was fastest during the first 20 s, subsequently the lesion growth slowed reaching a steady state after 100 s, ii) positioning the ground electrode directly opposite the catheter tip (optimal) produced a larger lesion, and iii) a constant tip temperature maintained a constant maximum tissue temperature; b) for CPRFA: i) the lesion growth was fastest during the first 20 s and then the lesion growth slowed; however, the lesion size did not reach steady state even after 600 s suggesting that longer durations of energy delivery may result in wider and deeper lesions, ii) the temperature-dependent electrical conductivity of the tissue is responsible for this continuous lesion growth, and iii) an optimal ground electrode location resulted in a slightly larger lesion and higher ablation efficiency.
Jain
M K
MK
National Science Foundation/Engineering Research Center, Durham, NC, USA. mkj@eel-mail.mc.duke.edu
Wolf
P D
PD
D001145:Arrhythmias, Cardiac / Q000628:therapy; D017115:Catheter Ablation; D003198:Computer Simulation; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008954:Models, Biological; D008962:Models, Theoretical; D009206:Myocardium / Q000473:pathology; D011846:Radio Waves; D013696:Temperature; D013997:Time Factors