Catheter contact angle influences local impedance drop during
radiofrequency catheter ablation: Insight from a porcine experimental
study with 2 different LI-sensing catheters
Abstract
Background: Local impedance (LI) can indirectly measure catheter contact
and tissue temperature during radiofrequency catheter ablation (RFCA).
However, data on the effects of catheter contact angle on LI parameters
are scarce. This study aimed to evaluate the influence of catheter
contact angle on LI changes and lesion size with 2 different LI-sensing
catheters in a porcine experimental study. Methods: Lesions were created
by the INTELLANAV MiFi™ OI (MiFi) and the INTELLANAV STABLEPOINT™
(STABLEPOINT). RFCA was performed with 30 watts and a duration of 30
seconds. The CF (0, 5, 10, 20, and 30 g) and catheter contact angle
(30°, 45°, and 90°) were changed in each set (n=8 each). The LI rise, LI
drop, and lesion size were evaluated. Results: The LI rise increased as
CF increased. There was no angular dependence with the LI rise under all
CFs in the MiFi. On the other hand, the LI rise at 90° was lower than at
30° under 5 and 10 g of CF in STABLEPOINT. The LI drop increased as CF
increased. Regarding the difference in catheter contact angles, the LI
drop at 90° was lower than that at 30° for both catheters. The maximum
lesion widths and surface widths were smaller at 90° than at 30°,
whereas there were no differences in lesion depths. Conclusion: The LI
drop and lesion widths at 90° were significantly smaller than those at
30°, although the lesion depths were not different among the 3 angles
for the MiFi and STABLEPOINT.