Haverkamp W, Hindricks G, Gulker H, Rissel U, Pfennings W, Borggrefe M, Breithardt G
Department of Cardiology-Angiology, University Hospital, Münster, Germany, FR.
Pacing Clin Electrophysiol. 1989 Jan;12(1 Pt 2):187-95. doi: 10.1111/j.1540-8159.1989.tb02646.x.
Within the last years, a variety of different energy sources has been investigated to test their feasibility for catheter ablation of myocardial tissue. This report summarizes our experience of the use of radiofrequency alternating current (500 kHz, unipolar mode) for coagulation of ventricular myocardium in canine experiments. Under standardized in vitro conditions, we found a significant correlation between actually delivered radiofrequency energy and assessed myocardial necrosis (r = 0.87). However, this did not hold for percutaneous application of radiofrequency alternating current to the beating dog heart (r = 0.32). In the intact dog heart, the size of induced lesions paralleled catheter contact pressure which was varied until ST-egment elevation was either 0-2 mV or 5-7 mV. However, no statistical significant differences in either calculated energy or tissue impedance were observed. Under in vivo conditions, a significant improvement in the predictability of the resulting size of lesions was observed when catheter tip temperature, measured via a built-in Ni/CrNi thermoelement, was monitored (r = 0.07). Changes in tip temperature during coagulation also indicated the quality of catheter contact, catheter damage and the appearance of carbonization at the tip of the ablation catheter. Total perforation of the myocardial wall and proarrhythmogenic effects were only rarely observed. In conclusion, catheter coagulation of myocardial tissue using radiofrequency energy can be considered as safe and effective. Since changes in catheter tip temperature occurring during coagulation were found to predict the extent of induced tissue necrosis, the development of temperature controlled radiofrequency devices seems promising and necessary.
在过去几年中，人们对多种不同的能源进行了研究，以测试它们用于心肌组织导管消融的可行性。本报告总结了我们在犬类实验中使用射频交流电（500kHz，单极模式）凝固心室心肌的经验。在标准化的体外条件下，我们发现实际输送的射频能量与评估的心肌坏死之间存在显著相关性（r = 0.87）。然而，对于在跳动的犬心脏上经皮施加射频交流电，情况并非如此（r = 0.32）。在完整的犬心脏中，诱发损伤的大小与导管接触压力平行，导管接触压力不断变化，直至ST段抬高为0 - 2mV或5 - 7mV。然而，在计算能量或组织阻抗方面未观察到统计学上的显著差异。在体内条件下，当通过内置的镍/镍铬热电偶监测导管尖端温度时，观察到所产生损伤大小的可预测性有显著改善（r = 0.07）。凝固过程中尖端温度的变化也表明了导管接触的质量、导管损伤以及消融导管尖端碳化的出现。心肌壁的完全穿孔和促心律失常作用仅很少观察到。总之，使用射频能量进行心肌组织导管凝固可被认为是安全有效的。由于发现凝固过程中导管尖端温度的变化可预测诱导的组织坏死程度，开发温度控制的射频设备似乎很有前景且很有必要。
