The Hull Family Cardiac Fibrillation Management Laboratory, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network Toronto, Ontario, Canada.
Arrhythmia Unit, Hospital Universitario Quirónsalud Madrid, Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC).
Heart Rhythm. 2021 Oct;18(10):1772-1779. doi: 10.1016/j.hrthm.2021.06.1189. Epub 2021 Jun 26.
The safety and efficacy parameters for bipolar radiofrequency (RF) ablation are not well defined.
The purpose of this study was to investigate the safe range of power, utility of transmyocardial bipolar electrogram (EGM) amplitude, and circuit impedance in ablation monitoring.
Sixteen beating ex vivo human and swine hearts were studied in a Langendorff setup. Ninety-two bipolar ablations using two 4-mm irrigated catheters were performed at settings of 20-50 W, 60 seconds, and 30 mL/min irrigation in the left ventricle.
For low-power ablations (20 and 30 W), transmurality was observed in 29 of 38 (76%) and 10 of 28 (36%) ablations for tissue thickness ≤17 mm and >17 mm, respectively. For high-power ablations (40 and 50 W), transmurality was observed in 5 of 7 (71%) and 7 of 19 (37%) ablations for tissue thickness ≤17 mm and >17 mm, respectively. Steam pop occurrence for low- and high-power ablations was 11 of 66 (16%) and 16 of 26 (62%), respectively (P = .0001), respectively. Lesion depth (limited by transmurality) was 12.0 ± 5.7 mm and 12.3 ± 5.8 mm, respectively (P = 1). Transmyocardial EGM amplitude decrement >60% strongly predicted transmurality (area under the curve [AUC] 0.8), and circuit impedance decrement >26% predicted steam pops (AUC 0.75). Half-normal saline did not affect transmurality or incidence of steam pops compared to normal saline irrigation.
Bipolar RF ablation at power of 20-30 W provided an ideal balance of safety and efficacy, whereas power ≥40 W should be used with caution due to the high incidence of steam pops. Lesion transmurality monitoring and steam pop avoidance were best achieved using transmyocardial bipolar EGM voltage and circuit impedance, respectively.
双极射频（RF）消融的安全性和有效性参数尚未得到很好的定义。
本研究旨在探讨功率安全范围、心肌内双极电图（EGM）幅度的实用性以及消融监测中的电路阻抗。
在 Langendorff 装置中研究了 16 个跳动的体外人心和猪心。在左心室中，使用两个 4mm 灌流导管进行了 92 次双极消融，设置为 20-50W、60 秒和 30mL/min 灌流。
对于低功率消融（20 和 30W），组织厚度≤17mm 的 38 次消融中有 29 次（76%）和组织厚度>17mm 的 28 次消融中有 10 次（36%）出现透壁性。对于高功率消融（40 和 50W），组织厚度≤17mm 的 7 次消融中有 5 次（71%）和组织厚度>17mm 的 19 次消融中有 7 次（37%）出现透壁性。低功率和高功率消融的蒸汽弹出发生率分别为 11 次（16%）和 16 次（62%）（P=0.0001）。病变深度（受透壁性限制）分别为 12.0±5.7mm 和 12.3±5.8mm（P=1）。心肌内 EGM 幅度下降>60%强烈预测透壁性（曲线下面积[AUC]0.8），而电路阻抗下降>26%预测蒸汽弹出（AUC 0.75）。与生理盐水灌流相比，半生理盐水并未影响透壁性或蒸汽弹出的发生率。
功率为 20-30W 的双极 RF 消融提供了安全性和有效性的理想平衡，而功率≥40W 由于蒸汽弹出的发生率较高，应谨慎使用。心肌内双极 EGM 电压和电路阻抗分别用于监测病变透壁性和避免蒸汽弹出效果最佳。
