Stühlinger Markus, Steinwender Clemens, Schnöll Felix, Winter Siegmund, Freihoff Fritz, Wurtz Sabine, Hintringer Florian
Department of Cardiology, Medical University of Innsbruck, Innsbruck, Austria.
J Cardiovasc Electrophysiol. 2008 Mar;19(3):242-6. doi: 10.1111/j.1540-8167.2007.01049.x. Epub 2007 Dec 12.
Radiofrequency (RF) catheter ablation targeting the slow pathway is currently the most effective treatment for patients with atrioventricular nodal reciprocating tachycardia (AVNRT). Gold exhibits a more than four times greater thermal conductivity than platinum, and the creation of deeper lesions was demonstrated in ex vivo animal experiments. The current clinical trial was initiated to compare gold catheters with standard platinum-iridium (Pt-Ir) material and to analyze differences in the increase of power or temperature as a function of time during RF ablation.
A prospective, randomized multicenter study design was used to compare RF deliveries at the slow pathway with standard Pt-Ir tip catheters (128 patients), as well as gold alloy tip electrodes (124 patients) during AVNRT ablation.
Although there was a trend towards higher power delivery in the gold group (4.96 vs. 4.28 W/s), this trend was not statistically significant. Likewise, cumulative duration of all RF ablations, total procedure time, and power delivered at other time points were not significantly different between the groups. Also, the occurrence of AV-block and sensations of pain were similar in both treatment groups. However, charring on the catheter tip after the intervention was observed eightfold more frequently in the Pt-Ir group.
In conclusion, power delivery cannot be significantly increased by RF ablation of AVNRT with gold electrodes. But the electrode material seems to be safe and well-tolerated and specifically did not increase the risk of AV-block. The significant reduction of coagulum formation on gold tips suggests a possible advantage of this material beyond its better conduction properties.
针对慢径路的射频（RF）导管消融术目前是房室结折返性心动过速（AVNRT）患者最有效的治疗方法。金的热导率比铂高四倍多，并且在体外动物实验中已证明其能形成更深的损伤。开展本次临床试验以比较金导管与标准铂铱（Pt-Ir）材质的导管，并分析射频消融期间功率或温度随时间增加的差异。
采用前瞻性、随机多中心研究设计，比较在AVNRT消融期间使用标准Pt-Ir尖端导管（128例患者）以及金合金尖端电极（124例患者）在慢径路进行的射频传递。
尽管金组有较高功率传递的趋势（4.96对4.28W/s），但该趋势无统计学意义。同样，两组之间所有射频消融的累积持续时间、总手术时间以及其他时间点传递的功率均无显著差异。此外，两组中房室传导阻滞的发生率和疼痛感觉相似。然而，干预后在Pt-Ir组中观察到导管尖端炭化的频率是金组的八倍。
总之，使用金电极进行AVNRT的射频消融不能显著提高功率传递。但电极材料似乎安全且耐受性良好，尤其不会增加房室传导阻滞的风险。金尖端上凝固物形成的显著减少表明这种材料除了具有更好的传导性能外可能还有其他优势。
