Abstract 17321: Invivo Left Ventricular Contact Force and Impedance Analysis Using a Retrograde Transaortic Approach
Background: Little is reported about invivo contact force (CF) during left ventricular (LV) mapping and catheter ablation for ventricular tachycardia (VT). The aim of this study was to evaluate CF during LV mapping and RF ablation.
Methods: In six patients undergoing catheter ablation for VT, LV mapping was performed using a retrograde transaortic approach. A novel commercially available CF catheter and a 3D mapping system were used. The operator was blinded to the CF. Catheter stability was assessed using the coefficient of variance (COV=standard deviation of CF/average of CF). Data was analyzed according to 11 predefined areas (Figure 1). CF data of 1.2 seconds/ mapping point (pts) and the first 30 seconds of each ablation were analyzed.
Results: 1113 mapping pts and 62 ablations were analyzed. During LV mapping, mean CF was 16.8±13.3g (Table). CF was significantly higher in the basal-inferior and basal-lateral areas than in the other areas (Table). Low CF (<10g) was recorded in 430 pts (39%). High CF (>=40g) was recorded in 83 pts (7%), particularly in the basal-inferior and basal-lateral areas. Extremely high CF (>=100g) was recorded at 4 points (0.4%). COV was significantly larger, indicating more unstable catheter position, in the basal-lateral area (Figure 1). As for 62 RF applications, no significant correlation between initial CF and initial impedance was noted. Impedance dropped during the first 30 seconds of RF ablation from 112±9 to 102±8 Ohm (P = 0.15).
Conclusions: CF during retrograde LV mapping ranges from <10g to >100g. Low CF (<10g) was observed in ∼40% of pts. CF and impedance showed no significant correlation.
- © 2012 by American Heart Association, Inc.