Kawano Daisuke, Mori Hitoshi, Kato Ritsushi, Tsutsui Kenta, Ikeda Yoshifumi, Sumitomo Naokata, Fukaya Hidehira, Iwagana Shiro, Nakano Shintaro, Muramatsu Toshihiro, Matsumoto Kazuo
Department of Cardiology, Saitama Medical University International Medical Center, Saitama, Japan.
Department of Pediatric Cardiology, Saitama Medical University International Medical Center, Saitama, Japan.
J Cardiovasc Electrophysiol. 2021 Aug;32(8):2069-2076. doi: 10.1111/jce.15136. Epub 2021 Jul 7.
The local impedance (LI) reflects the electrical catheter-tissue coupling and correlates with the local tissue temperature. However, there have been few clinical studies showing the recommended method for LI monitoring catheters. This study aimed to investigate the optimal ablation setting for this catheter in an in vitro experimental model.
LI monitoring catheters were used in an excised swine heart experimental model. The tissue contact force (CF) was directly monitored from an external weight scale. Radiofrequency ablation was performed with a combination of various energy power settings (30, 40, and 50 W), and various CFs (10, 30, and 50 g) for 60 s. The correlation between the LI-related indexes, power, and CF with the lesion formation was statistically analyzed.
A positive correlation between the LI or lesion formation and CF was observed under all powers. Although the LI drop always correlated with the maximum lesion depth, lesion diameter, and lesion volume, the coefficient of the correlation value was lower under a high CF (lesion depth, diameter, and volume; 10 g, r = 0.8064, r = 0.8389, r = 0.8477; 30 g, r = 0.7590, r = 0.8063, r = 0.8060; 50 g r = 0.5555, r = 0.5701, and r = 0.5678, respectively). Steam pops occurred only under a 50 W ablation and the LI drop cutoff value for steam pops was 46 Ω.
The same LI drop did not always lead to the same lesion size when the CF differed. Monitoring the LI and not exceeding 46 Ω would be useful for a safe ablation.
局部阻抗（LI）反映了电导管与组织的耦合情况，并与局部组织温度相关。然而，很少有临床研究表明LI监测导管的推荐方法。本研究旨在体外实验模型中探究该导管的最佳消融设置。
在切除的猪心脏实验模型中使用LI监测导管。通过外部秤直接监测组织接触力（CF）。采用不同能量功率设置（30、40和50W）与不同CF（10、30和50g）组合进行60秒的射频消融。对LI相关指标、功率和CF与病变形成之间的相关性进行统计学分析。
在所有功率下，均观察到LI或病变形成与CF之间呈正相关。尽管LI下降始终与最大病变深度、病变直径和病变体积相关，但在高CF下相关系数值较低（病变深度、直径和体积；10g时，r = 0.8064，r = 0.8389，r = 0.8477；30g时，r = 0.7590，r = 0.8063，r = 0.8060；50g时，r分别为0.5555、0.5701和0.5678）。仅在50W消融时出现蒸汽爆裂声，蒸汽爆裂声的LI下降临界值为46Ω。
当CF不同时，相同的LI下降并不总是导致相同的病变大小。监测LI且不超过46Ω有助于安全消融。
