Abstract 17335: Visual or Tactile Feedback: Which One is More Important for Catheter Ablation?
Introduction: Contact Force between the ablation electrode and the targeted tissue is important in determining lesion size. Visual and tactile feedbacks together are clinically used to assess catheter stability and contact. The aim of the study was to compare the contact pressure measured with visual and tactile feedbacks together or alone in an experimental model.
Method: An in vitro experimental setup was devised to replicate the task of manual catheter manipulation. The setup included a catheter in a flushed sheath, with a tissue model at the catheter tip. The tissue model was instrumented with a load cell to track and record force applied to the tissue model by the catheter. Evaluators were asked to identify distinct levels of force at 3 different targets: 1) first contact with the target, ablative contact, and maximum contact using randomly combinations of senses: 1) visual only, by observing fluoroscopic image while “blinded” to touch; 2) tactile feedback only, blinded to fluoroscopy; 3) both tactile and visual feedback. Discrete force levels were recorded on the evaluator's cues. The tactile and visual methods were compared with the visual tactile (considered the gold standard and the reference method) for agreement precision and accuracy.
Results: Nineteen evaluators from 3 different institutions participated in the study. Compared to the reference method, tactile and visual methods had a mean error of 3.9±23.0 (p=0.519) and 1.9±14.8 (p=0.622) respectively for first contact, and 8.2±21.2 (p=0.155) and 5.8±13.8 (p=0.123) respectively for ablation contact. The relatively small errors with vision method were clinically important, though not statistically significant. For maximum contact, tactile method had significant disagreement (error 35.6±34.4, p=0.001) while error for vision was quite small (2.9±7.8, p=0.168). Using regression approach for assessing the equality of test method to reference method, yielded similar findings.
Conclusions: The visual feedback is in better agreement with the reference method (visual+tactile) compared to the tactile approach. These results are extremely important both for manual and robotic navigation and suggest that more objective feedback of contact pressure could be valuable during ablation procedures.
- © 2010 by American Heart Association, Inc.