CELLULAR ELECTROPHYSIOLOGICAL CHANGES INDUCED IN-VITRO BY RADIOFREQUENCY CURRENT - COMPARISON WITH ELECTRICAL ABLATION
CELLULAR ELECTROPHYSIOLOGICAL CHANGES INDUCED IN-VITRO BY RADIOFREQUENCY CURRENT - COMPARISON WITH ELECTRICAL ABLATION
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DOI：
10.1111/j.1540-8159.1995.tb02523.x
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发表时间：
1995-02-01
影响因子：
1.8
通讯作者：
KADISH, A
中科院分区：
文献类型：
--
作者：
GE, YZ;SHAO, PZ;KADISH, A
本研究的目的是检查体外犬心外膜制备中射频能量输送的细胞电生理效应，并将其与类似制备中的高能电消融效果进行比较。10焦耳的直流电能量或40伏特的射频能量由6法国2毫米尖端导管输送到2 X 3厘米的心外膜带表面，并与Tyrode's溶液混合。直流电能量输送产生一个凹坑和中心坏死区，周围是可存活但受损的边缘组织，从能量/输送部位延伸至10-12毫米。细胞电生理异常包括静息负膜电位减少、峰值dV/dT下降、动作电位振幅下降和动作电位持续时间（APD）减少，这些异常与距离火山口边缘的距离近似线性相关。此外，活细胞和不兴奋细胞经常穿插。在距火山口边缘2 ~ 5mm处，36.4%的细胞不可兴奋，而其他细胞表现出正常的动作电位特征。相反，射频电流产生一个中心坏死区，周围有一个较小的边界区。与直流电能量造成的细胞损伤在质量上类似，但从陨石坑边缘只延伸到6-8毫米。此外，在消融部位2毫米范围内记录的细胞内电位存在严重异常，而在更远的地方只有轻微异常。病灶相对均匀。在距离消融部位2 ~ 5mm范围内，仅有2.6%的细胞不兴奋（与直流电相比P < 0.05）。总之，射频电流产生的病变比直流电消融产生的病变更小，更均匀。虽然边界区很小，但在射频电流能量输送后，存在部分去极化但存活的心肌区域。这些发现为射频电流能量输送后的一些临床观察提供了细胞基础。
The purpose of this study was to examine the cellular electrophysiological effects of radiofrequency energy delivery in an in vitro canine epicardial preparation and compare the effects to those of high energy electrical ablation in a similar preparation. Ten joules of direct current energy or 40 volts of radiofrequency energy were delivered by a 6 French 2-mm tip catheter to the epicardial surface of 2 X 3 cm epicardial strips superfused with Tyrode's solution. Direct current energy delivery produced a: crater and central zone of necrosis surrounded by a border zone of viable but damaged tissue that extended up to 10-12 mm from the site of energy/delivery. Cellular electrophysiological abnormalities that included a less negative resting membrane potential, decreased peak dV/dT, decreased action potential amplitude, and decreased action potential duration (APD) were approximately linearly related to the distance from the crater edge. In addition, viable and inexcitable cells were frequently interspersed. Between 2 and 5 mm from the crater edge, 36.4% of the cells were inexcitable whereas others displayed normal action potential characteristics, In contrast, radiofrequency current produced a central zone of necrosis surrounded by a smaller border zone. Cellular damage that was qualitatively similar to that produced by direct current energy extended only up to 6-8 mm from the edge of the crater. In addition, severe abnormalities were noted in intracellular potentials recorded within 2 mm of the ablation site, and only minor abnormalities further away. Lesions were relatively homogeneous. Between 2 and 5 mm from the ablation site only 2.6% of the cells were inexcitable (P < 0.05 vs direct current). In conclusion, radiofrequency current produces lesions that are smaller and more homogeneous than those produced by direct current ablation. Although the border zone is small, a region of partially depolarized but viable myocardium is present after radiofrequency current energy delivery. These findings provide a cellular basis for several clinical observations that have been made following radiofrequency current energy delivery.