Contact sensing provides a highly accurate means to titrate radiofrequency ablation lesion depth.
BACKGROUND
Transmural lesions are essential for efficacious ablation. There are, however, no accurate means to estimate lesion depth.


OBJECTIVE
Explore use of the electrical coupling index (ECI) from the EnSite Contact™ System as a potential variable for lesion depth estimation.


METHODS
Radiofrequency (RF) ablation lesions were created in atria and the thighs of swine using an irrigated RF catheter. Power was 30 W for 20 or 30 seconds intracardiac and 30-50 W for 10-60 seconds for the thigh. Intracardiac, the percentage change in ECI during ablation was compared with transmurality and collateral damage occurrence. For the thigh model, an algorithm estimating lesion depth was derived. Factors included: power, duration, and change in the ECI subcomponents (ΔECI+) during ablation. The ΔECI+ algorithm was compared to one using power and duration (PD) alone.


RESULTS
Intracardiac, lesions with ≥12% reduction in ECI were more likely to be transmural (92.3% vs. 59.4%, P < 0.001). Twenty-second lesions were less likely to cause collateral damage compared to 30 seconds (33% vs. 70%, P = 0.003), while transmurality was similar. With the thigh model, ΔECI+ had a better correlation than the PD algorithm (P < 0.01). Accuracy of the ΔECI+ algorithm was unimproved with inclusion of tip orientation, while PD improved (R(2) = 0.64).


CONCLUSIONS
Change in ECI provides evidence of transmural versus nontransmural swine intracardiac atrial lesions. A lesion depth estimation algorithm using ECI subcomponents is unaffected by tip orientation and is more accurate than using PD alone.


CONCLUSIONS
Use of ECI as a factor in a lesion depth algorithm may provide clinically valuable information regarding the efficacy of intracardiac RF ablation lesions.
New York University, New York, New York, USA. douglas.holmes@med.nyu.edu
Douglas
D
Holmes
Jeffrey M
JM
Fish
Israel A
IA
Byrd
Jeremy D
JD
Dando
Steven J
SJ
Fowler
Hong
H
Cao
James A
JA
Jensen
Harry A
HA
Puryear
Larry A
LA
Chinitz
D000465:Algorithms; D000818:Animals; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D006325:Heart Atria / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013552:Swine