Department of Electrophysiology, German Heart Center Munich, Technical University Munich, Munich, Germany.
J Cardiovasc Electrophysiol. 2021 Jun;32(6):1594-1599. doi: 10.1111/jce.15063. Epub 2021 May 12.
Steam pops are a rare complication associated with radiofrequency (RF) ablation and are hard to predict. The aim of this study was to assess the influence of coverage between the RF ablation electrode and cardiac tissue on steam pop incidence and lesion size.
An ex vivo model using porcine cardiac preparations and contact force sensing catheters was designed to perform RF ablations at different coverage levels between the RF electrode and cardiac tissue. During coverage level I, only the distal part of the ablation electrode was in contact with tissue. During coverage level II half of the ablation electrode, and during coverage level III the entire ablation electrode was embedded in tissue. RF applications (n = 60) at different coverage levels I-III were systematically performed using the same standardized ablation protocol. Ablations during coverage level III resulted in a significantly higher rate of steam pops (100%) when compared to ablations during coverage level II (10%) and coverage level I (0%), log rank p < .001. Coverage level I ablations resulted in significantly smaller lesion depths, diameters, and impedance drops when compared to higher coverage level ablations, p < .001. In the controlled ex vivo model, there was no difference in applied contact force or energy between different coverage levels.
The level of coverage between RF electrode, cardiac tissue, and the surrounding fluid significantly influenced the incidence of steam pops in an ex vivo setup. Larger coverage between RF electrode and tissue resulted in significantly larger lesion dimensions.
射频（RF）消融相关的蒸汽爆裂是一种罕见的并发症，难以预测。本研究旨在评估 RF 消融电极和心脏组织之间的覆盖程度对蒸汽爆裂发生率和病变大小的影响。
设计了一个使用猪心标本和接触力感应导管的离体模型，以在 RF 电极和心脏组织之间的不同覆盖程度下进行 RF 消融。在覆盖程度 I 期间，只有消融电极的远端部分与组织接触。在覆盖程度 II 期间，消融电极的一半嵌入组织中，而在覆盖程度 III 期间，整个消融电极嵌入组织中。使用相同的标准化消融方案，在不同的覆盖程度 I-III 下系统地进行 RF 应用（n=60）。与覆盖程度 II（10%）和覆盖程度 I（0%）相比，覆盖程度 III 下的消融导致蒸汽爆裂的发生率明显更高（100%对 10%，log 秩检验，p<0.001）。与较高的覆盖程度消融相比，覆盖程度 I 消融导致的病变深度、直径和阻抗下降明显更小，p<0.001。在受控的离体模型中，不同覆盖程度之间的应用接触力或能量没有差异。
RF 电极、心脏组织和周围液体之间的覆盖程度显著影响离体模型中蒸汽爆裂的发生率。RF 电极和组织之间更大的覆盖程度导致病变尺寸明显更大。
