Tsutsui Kenta, Kawano Daisuke, Mori Hitoshi, Kato Ritsushi, Ikeda Yoshifumi, Sumitomo Naokata, Fukaya Hidehira, Iwanaga Shiro, Nakano Shintaro, Muramatsu Toshihiro, Matsumoto Kazuo
Department of Cardiology, Saitama Medical University International Medical Center, Hidaka, Japan.
Department of Pediatric Cardiology, Saitama Medical University International Medical Center, Hidaka, Japan.
J Cardiovasc Electrophysiol. 2021 Dec;32(12):3187-3194. doi: 10.1111/jce.15253. Epub 2021 Sep 30.
Local impedance (LI) has emerged as a new technology that informs on electrical catheter-tissue coupling during radiofrequency (RF) ablation. Recently, IntellaNav StablePoint, a novel LI-enabled catheter that equips contact force (CF) sensing, has been introduced. Although StablePoint and its predecessor IntellaNav MiFi OI share the common technology that reports LI, distinct mechanics for LI sensing between the two products raise a concern that the LI-RF lesion formation relationship may differ.
In an ex vivo swine cardiac tissue model, we investigated the initial level and range of a reduction in LI during a 60-s RF ablation and the resultant lesion characteristics at nine combinations of three energy power (30, 40, and 50 W) and CF (10, 30, and 50 g) steps. Correlations and interactions between CF, LI, wattage, and formed lesions were analyzed. Incidence of achieving LI drop plateau and that of a steam pop were also determined.
Positive correlations existed between CF and initial LI, CF and absolute/relative LI drop, CF and lesion volume, and LI drop and lesion volume. At the same LI drop, wattage-dependent gain in lesion volume was observed. Steam pops occurred in all CF steps and the prevalence was highest at 50 W. LI drop predicted a steam pop with a cutoff value at 89Ω.
In StablePoint, wattage crucially affects LI drop and lesion volume. Because 30 W ablation may by underpowered for intramural lesion formation and 50 W often resulted in a steam pop, 40 W appears to achieve the balance between the safety and efficacy.
局部阻抗（LI）已成为一项新技术，可在射频（RF）消融期间反映电导管与组织的耦合情况。最近，推出了一种新型的具有LI功能的导管IntellaNav StablePoint，该导管配备了接触力（CF）传感功能。尽管StablePoint及其前身IntellaNav MiFi OI共享报告LI的通用技术，但两种产品之间用于LI传感的不同机制引发了人们对LI与RF病变形成关系可能不同的担忧。
在离体猪心脏组织模型中，我们研究了60秒RF消融期间LI降低的初始水平和范围，以及在三种能量功率（30、40和50W）和CF（10、30和50g）步骤的九种组合下产生的病变特征。分析了CF、LI、瓦特数和形成的病变之间的相关性和相互作用。还确定了达到LI下降平台期的发生率和蒸汽泡的发生率。
CF与初始LI、CF与绝对/相对LI下降、CF与病变体积以及LI下降与病变体积之间存在正相关。在相同的LI下降情况下，观察到病变体积的瓦特数依赖性增加。在所有CF步骤中均出现蒸汽泡，在50W时发生率最高。LI下降预测蒸汽泡的临界值为89Ω。
在StablePoint中，瓦特数对LI下降和病变体积有至关重要的影响。由于30W消融可能不足以形成壁内病变，而50W经常导致蒸汽泡，40W似乎在安全性和有效性之间实现了平衡。
