Graduate Department of Computer Science and Engineering, The University of Aizu, Aizuwakamatsu, Fukushima 965-8580, Japan.
Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, Meguro, Tokyo 153-8515, Japan.
Med Eng Phys. 2024 Sep;131:104226. doi: 10.1016/j.medengphy.2024.104226. Epub 2024 Aug 21.
Compared to traditional unipolar radiofrequency ablation (RFA), bipolar RFA offers advantages such as more precise heat transfer and higher ablation efficiency. Clinically, myocardial baseline impedance (BI) is one of the important factors affecting the effectiveness of ablation. We aim at finding suitable ablation protocols and coping strategies by analyzing the ablation effects and myocardial impedance changes of bipolar RFA under different BIs. In this research, a three-dimensional local myocardial computer model was constructed for bipolar RFA simulation, and in vitro experimental data were used to validate accuracy. Four fixed low-power levels (20 W, 25 W, 30 W, and 35 W) and six myocardial BIs (91.02 Ω, 99.83 Ω, 111.03 Ω, 119.77 Ω, 130.03 Ω, and 135.45 Ω) were set as initial conditions, with an ablation duration of 120-s. In the context of low-power and long-duration (LPLD) ablation, the maximum TID (TID) decreased by 21-32 Ω, depending on the BI. In cases where steam pop did not occur, TID increased with the increase in power. For the same power, there was no significant difference in TID for the range of BIs. In cases where steam pop occurred, for every 1 Ω increase in BI, TID increased by 0.34-0.41 Ω. The simulation results also showed that using a higher power resulted in a smaller decrease in TID. This study provided appropriate ablation times and impedance decrease ranges for bipolar LPLD RFA. The combination of 25 W for 120-s offered optimal performance when considering effectiveness and safety simultaneously.
与传统的单极射频消融（RFA）相比，双极 RFA 具有更精确的热传递和更高的消融效率等优点。临床上，心肌基础阻抗（BI）是影响消融效果的重要因素之一。我们旨在通过分析不同 BI 下双极 RFA 的消融效果和心肌阻抗变化，找到合适的消融方案和应对策略。在这项研究中，构建了一个用于双极 RFA 模拟的三维局部心肌计算机模型，并使用离体实验数据进行了准确性验证。设置了四个固定低功率水平（20 W、25 W、30 W 和 35 W）和六个心肌 BI（91.02 Ω、99.83 Ω、111.03 Ω、119.77 Ω、130.03 Ω 和 135.45 Ω）作为初始条件，消融持续时间为 120 s。在低功率和长时间（LPLD）消融的情况下，TID 最大降低了 21-32 Ω，具体取决于 BI。在未发生蒸汽爆裂的情况下，TID 随功率的增加而增加。对于相同的功率，BI 范围内的 TID 没有显著差异。在发生蒸汽爆裂的情况下，BI 每增加 1 Ω，TID 增加 0.34-0.41 Ω。模拟结果还表明，使用更高的功率会导致 TID 减小幅度减小。本研究为双极 LPLD RFA 提供了合适的消融时间和阻抗降低范围。考虑到有效性和安全性，25 W 持续 120 s 的组合表现最佳。
