Experimental Model
A circulating saline bath (400 mL/min, NaCl 3.5 g/L) isotonic to blood,
a submersible load cell (KW-201, Tanita, Tokyo, Japan), and a
deflectable sheath were assembled. The load cell was installed on the
bottom of the bath with 5.0 L saline at 37°C, and a section of the left
ventricular myocardium was placed on the ground plate on a load cell
apparatus. CF applied to the overlying myocardial tissue through the
ablation catheter was measured by the load cell in order to provide the
same conditions between the TactiCathTM SE (which has
direct CF-sensing capability) and FlexAbilityTM SE
catheters. The accuracy of CF in this model was verified by a CF-sensing
catheter with EnSite Precision (Abbott) mapping system as shown in
Supplementary Figure 1. Briefly, the correlation coefficient between the
CF measured by the load cell and CF in the TactiCathTMSE catheter was R = 0.97 for perpendicular catheter placement and R =
0.77 for parallel catheter placement. Temperature, power and impedance
values were continuously monitored during RF delivery using the EnSite
Precision cardiac mapping system.