Lesion assessment
After RF delivery, lesion surface was measured as shown in Figure 1C. The myocardium was cross-sectioned along the surface length at the level of each lesion. The cross-sectioned area was also measured as shown in Figure 1C. Each lesion was measured with a dial caliper with a resolution of 0.1 mm by one observer; the observer was not blinded to the lesion protocol. Surface area and lesion volume were calculated from the following formulae:
Lesion volume = (1/6) × π × (e2 × d + c× a2/2)
Lesion surface area = π × a/2 × b/2 (4)
Lesions with steam-pops were excluded from the lesion size analysis.