Oeff M, Langberg J J, Chin M C, Finkbeiner W E, Scheinman M M
Department of Medicine, University of California San Francisco.
Pacing Clin Electrophysiol. 1992 Aug;15(8):1167-76. doi: 10.1111/j.1540-8159.1992.tb03120.x.
Multiple sequential radiofrequency energy was applied in the left and right ventricles of 24 dogs to produce large ablated areas limited to endocardial and subendocardial regions. Endocardial ablation was performed in nine dogs with normal ventricles and 15 that had survived remote myocardial infarcts, three with inducible sustained monomorphic ventricular tachycardia. A quadripolar catheter was positioned either at the site of earliest ventricular activation during induced monomorphic ventricular tachycardia or at circumscribed areas of the left ventricle. Radiofrequency energy was delivered between two adjacent poles of the catheter, successively applying radiofrequency energy to the distal, middle, and proximal electrode pairs; this was repeated 9 to 11 times with the catheter in a slightly different position. A cumulative energy of 9,688 +/- 4,191 joules resulted in an ablated endocardial/subendocardial surface area of 4.7 +/- 2.2 cm2 (range 2.4-10 cm2, maximum depth 4 mm). Sustained tachycardia was not inducible by aggressive programmed ventricular stimulation in the dogs with previously inducible tachycardia, indicating successful ablation of the tachycardia foci. Only seven normal dogs were available for electrophysiological studies; three were used in acute and four in chronic studies. Ventricular tachycardia was not induced in the remaining dogs either before or after radiofrequency ablation, indicating the lack of an arrhythmogenic effect of this method. Histologic examination was performed in all nine normal dogs (five were sacrificed for acute pathological examination) as well as in the 15 with myocardial infarction. The late pathological examination of the radiofrequency lesion in these 19 animals showed homogeneous areas of coagulation necrosis and endocardial proliferation. Thus, this modified technique of radiofrequency ablation produced large homogeneous endocardial/subendocardial scars suitable for treating ventricular tachycardia and showed no evidence of an arrhythmogenic influence.
对24只犬的左、右心室施加多次连续射频能量，以产生仅限于心内膜和心内膜下区域的大消融区。对9只心室正常的犬以及15只曾患陈旧性心肌梗死（其中3只可诱发持续性单形性室性心动过速）的犬进行心内膜消融。将四极导管置于诱发单形性室性心动过速时最早发生心室激动的部位或左心室的限定区域。在导管的两个相邻极之间传递射频能量，依次对远端、中间和近端电极对施加射频能量；导管位置略有不同时重复此操作9至11次。累积能量9688±4191焦耳导致心内膜/心内膜下消融表面积为4.7±2.2平方厘米（范围2.4 - 10平方厘米，最大深度4毫米）。在先前可诱发心动过速的犬中，积极的程控心室刺激不能诱发持续性心动过速，表明心动过速病灶消融成功。仅7只正常犬可用于电生理研究；3只用于急性研究，4只用于慢性研究。其余犬在射频消融前后均未诱发室性心动过速，表明该方法无致心律失常作用。对所有9只正常犬（5只处死后进行急性病理学检查）以及15只患心肌梗死的犬进行组织学检查。对这19只动物射频损伤的晚期病理学检查显示有均匀的凝固性坏死区和心内膜增生。因此，这种改良的射频消融技术产生了适合治疗室性心动过速的大的均匀的心内膜/心内膜下瘢痕，且未显示有致心律失常影响的证据。
