Background. Catheter ablation failure poses a clinical challenge for epicardial or intramural ventricular arrhythmia (VA); however, guidewire ablation within the coronary venous system (CVS) may be effective and safe for targeting VAs. Methods. The ex vivo phase included four steps. In step 1, the steam pop incidence rates during guidewire ablation at power settings of 5, 10, 15, 20, and 25 W were analyzed using 10 mm- and 20 mm-tip guidewires. In step 2, guidewire ablation was performed for application durations of 10, 20, 30, 40, 50, 60, and 90 s, and the lesion size was measured. In step 3, the effects of saline infusion (0, 1, 2, 3, and 4 mL/min) on lesion dimensions and steam pop formation were examined. In step 4, an orthogonal array was constructed to obtain the optimal guidewire ablation parameters. In the in vivo phase, guidewire ablation within the CVS was performed in three dogs, and the lesion features in 10 days after ablation were observed. Results. In step 1, the steam pop incidence rates at 5, 10, 15, 20, and 25 W were 0%, 0%, 12.5%, 62.5%, and 100% using the 10 mm-tip guidewires and 0%, 0%, 0%, 25%, and 75% using the 20 mm-tip guidewires, respectively. In step 2, we found that the lesion areas increased with an increase in the ablation duration (the maximum lesion diameters at 30, 60, and 90 s were 4.9 ± 0.4, 7.0 ± 0.8, and 9.2 ± 0.7 mm in the 10 mm group and 3.2 ± 0.5, 4.5 ± 0.4, and 5.3 ± 0.7 mm in the 20 mm-tip group, respectively). In step 3, we observed that saline infusion was negatively correlated with ablation lesions but had a lower risk of steam pop. The optimal parameters for the 20 mm-tip guidewire ablation were 15 W, 50 s, and 2 mL/min or 20 W, 70 s, and 2 mL/min. In the in vivo phase, effective ablation lesions with maximum and minimum diameters of 3.2 ± 0.3 and 2.8 ± 0.5 mm, respectively, were created by the guidewires during the 10-day observation period after ablation. Conclusion. This novel radiofrequency guidewire ablation technique can feasibly create effective lesions within the CVS, which may improve the efficacy of catheter ablation for challenging epicardial or intramural VA.

中文翻译：

---

冠状静脉系统内导丝消融治疗心外膜或壁内室性心律失常：生物物理特征的临床前研究

背景。导管消融失败给心外膜或壁内室性心律失常（VA）带来了临床挑战；然而，冠状静脉系统 (CVS) 内的导丝消融对于靶向 VA 可能是有效且安全的。方法。离体阶段包括四个步骤。在步骤 1 中，使用 10 mm 和 20 mm 尖端导丝分析了功率设置为 5、10、15、20 和 25 W 时导丝消融过程中的蒸汽爆裂发生率。在步骤2中，进行导丝消融，持续时间为10、20、30、40、50、60和90秒，并测量病变大小。在步骤 3 中，检查了盐水输注（0、1、2、3 和 4 mL/min）对病变尺寸和蒸汽爆裂形成的影响。步骤4构建正交阵列以获得最佳导丝消融参数。在体内阶段，对3只犬进行CVS内导丝消融，观察消融后10天的病变特征。结果。在步骤 1 中，使用 10 mm 尖端导丝时，5、10、15、20 和 25 W 下的蒸汽爆裂发生率分别为 0%、0%、12.5%、62.5% 和 100%，使用 0%、0%使用 20 毫米尖端导丝分别为 、0%、25% 和 75%。在步骤2中，我们发现病灶面积随着消融持续时间的增加而增加（10 mm组中30、60和90秒时的最大病灶直径分别为4.9±0.4、7.0±0.8和9.2±0.7mm） 20 毫米尖端组中分别为 3.2 ± 0.5、4.5 ± 0.4 和 5.3 ± 0.7 毫米）。在步骤3中，我们观察到盐水输注与消融病变呈负相关，但蒸汽爆裂的风险较低。20 mm 尖端导丝消融的最佳参数为 15 W、50 s 和 2 mL/min 或 20 W、70 s 和 2 mL/min。在体内阶段，消融后10天的观察期内，导丝产生最大和最小直径分别为3.2±0.3和2.8±0.5毫米的有效消融病灶。结论。这种新颖的射频导丝消融技术可以在 CVS 内产生有效的损伤，这可能会提高导管消融治疗心外膜或壁内 VA 的疗效。