Ablation protocol
RF lesions were created on the LV epicardium with a Rhythmia HDx™ Mapping System (Boston Scientific, Maple Grove, MN, USA). The RF application was delivered with a constant power of 30 watts and a duration of 30 seconds. CF (0, 5, 10, 20, and 30 g) and the catheter contact angle (30°, 45°, and 90°) were changed in each set (total 120 lesions, n=8 each, Figure 2). The same experiment was performed with 2 different ablation catheters. The LI increases as the catheter contacts the tissue, and the LI decreases with the RF application. We defined the value of the LI increase above the baseline LI by the catheter contact as the LI rose and the absolute decrease in LI by the RF application as the LI dropped. The proportional values of the LI parameters were also evaluated to compare the 2 different catheters. The %LI rise was calculated as the LI rise divided by the baseline LI, and the %LI drop was calculated as the LI drop divided by the baseline LI.