Mehdirad A, Gaiser J, Baker P, West S, Lehmkuhl L, Yong P, Meimer J, Nelson S
Division of Cardiology, Ohio State University School of Medicine, Columbus 43210, USA.
J Interv Card Electrophysiol. 1998 Sep;2(3):279-84. doi: 10.1023/a:1009741105605.
Radiofrequency (RF) energy has been delivered to the tricuspid valve annulus (TVA) in humans with both 4 mm and 8 mm long catheter tip electrodes to treat atrial flutter. However, lesion volume with temperature controlled RF delivery systems has not been previously characterized.
In 10 anesthetized canines, a single pulse of temperature controlled RF energy at a 70 degrees C set point, 30 second duration was delivered with either a 7 Fr/4 mm tip or a 7 Fr/8 mm tip electrode in a position both anterolateral and posteroseptal to the tricuspid valve annulus (TVA). Surface echocardiogram was obtained prior and after ablation. The animals were sacrificed after ablation and the lesions underwent gross and histological examination.
Lesion size, tip temperature and power were related to tip electrode surface area (SA). Eight mm tips (SA = 59 mm2) tended to create significantly larger lesions than 4 mm tips (SA = 29 mm2). Median lesion volume was 22 vs. 1.5 mm3, respectively. Eight mm tips were also associated with higher power requirements and lower temperatures than 4 mm tips. Posteroseptal TVA lesions tended to be larger than anterolateral lesions. No significant complications were noted.
Using temperature controlled RF ablation, large lesions may be safely created on the canine TVA using 7 Fr catheters with 8 mm long tips.
在人类中，已使用4毫米和8毫米长的导管尖端电极将射频（RF）能量传递至三尖瓣环（TVA）以治疗心房扑动。然而，此前尚未对温度控制的射频传递系统所形成的损伤体积进行表征。
在10只麻醉的犬中，使用7 Fr/4毫米尖端或7 Fr/8毫米尖端电极，在三尖瓣环（TVA）的前外侧和后间隔位置，以70℃设定点、持续30秒的温度控制射频能量单脉冲进行传递。在消融前后获取体表超声心动图。消融后处死动物，对损伤进行大体和组织学检查。
损伤大小、尖端温度和功率与尖端电极表面积（SA）相关。8毫米尖端（SA = 59平方毫米）形成的损伤往往比4毫米尖端（SA = 29平方毫米）显著更大。中位损伤体积分别为22立方毫米和1.5立方毫米。8毫米尖端与4毫米尖端相比，还需要更高的功率且温度更低。后间隔TVA损伤往往比前外侧损伤更大。未观察到明显并发症。
使用温度控制的射频消融，使用带有8毫米长尖端的7 Fr导管可在犬TVA上安全地形成大的损伤。
