van Es René, Groen Marijn H A, Stehouwer Marco, Doevendans Pieter A, Wittkampf Fred H M, Neven Kars
Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands.
Department of Extracorporeal Circulation, St Antonius Hospital, Nieuwegein, The Netherlands.
J Cardiovasc Electrophysiol. 2019 Oct;30(10):2071-2079. doi: 10.1111/jce.14091. Epub 2019 Sep 12.
Recent studies demonstrated that irreversible electroporation (IRE) ablation may be an alternative method for thermal ablation for pulmonary vein isolation. Development of gaseous microemboli during catheter ablation might lead to asymptomatic ischemic events and is therefore an important research topic. Gas formation during arcing with direct current catheter ablation has been studied in the past, however not for nonarcing IRE-ablation.
The aim of the present study was to visualize, quantify, and characterize gas formation during nonarcing millisecond IRE-pulses using a multielectrode circular catheter.
In vitro, gas formation during IRE-pulses was studied using a high-speed imaging, direct volume measurements, and a bubble counter. Gas formation was compared between cathodal and anodal IRE-pulses and between a small and large catheter hoop diameter.
High-speed images showed the location and dynamics of gas formation during cathodal and anodal millisecond IRE-pulses. The direct volume measurements demonstrated a significantly larger volume for cathodal than for anodal IRE-pulses (P < .001), and no significant difference between small and large hoop diameters. A strong linear relationship was found between delivered charge and total gas volume (r = 0.99). Bubble counter measurements showed that cathodal IRE-pulses produced more and larger gas bubbles than anodal IRE-pulses. The ratio of total gas volume between cathodal and anodal IRE-pulses is different as predicted from electrolysis theory.
In vitro, millisecond anodal IRE-pulses produce significantly less and smaller gas bubbles than millisecond cathodal IRE-pulses. In vivo experiments are required to investigate the clinical implication of these observations.
最近的研究表明，不可逆电穿孔（IRE）消融可能是用于肺静脉隔离的热消融的替代方法。导管消融过程中气态微栓子的形成可能导致无症状性缺血事件，因此是一个重要的研究课题。过去曾对直流导管消融时电弧形成过程中的气体生成进行过研究，但未针对非电弧IRE消融进行研究。
本研究的目的是使用多电极环形导管可视化、量化并表征非电弧毫秒级IRE脉冲期间的气体生成情况。
在体外，使用高速成像、直接体积测量和气泡计数器研究IRE脉冲期间的气体生成。比较阴极和阳极IRE脉冲之间以及小和大导管环直径之间的气体生成情况。
高速图像显示了阴极和阳极毫秒级IRE脉冲期间气体生成的位置和动态。直接体积测量表明，阴极IRE脉冲的体积明显大于阳极IRE脉冲（P <.001），并且小环直径和大环直径之间没有显著差异。在输送电荷和总气体体积之间发现了很强的线性关系（r = 0.99）。气泡计数器测量表明，阴极IRE脉冲比阳极IRE脉冲产生更多更大的气泡。阴极和阳极IRE脉冲之间的总气体体积比与电解理论预测的不同。
在体外，毫秒级阳极IRE脉冲产生的气泡明显少于毫秒级阴极IRE脉冲，且气泡更小。需要进行体内实验来研究这些观察结果的临床意义。
