Goette A, Hartung W, Lesh M, Honeycutt C, Fleischman S, Swanson D, Langberg J
Carlyle Fraser Heart Center, Emory University Hospital, Atlanta, Ga 30322, USA.
Circulation. 1996 Sep 15;94(6):1449-55. doi: 10.1161/01.cir.94.6.1449.
Catheter ablation with radiofrequency energy is feasible in a limited subset of patients with ventricular tachycardia. The purpose of this study was to evaluate a technique for mapping and ablation of ventricular myocardium with the use of transcatheter subendocardial infusion.
A needle-tipped deflectable electrode catheter was used to deliver reagents to endocardial target sites. This was equipped with two central lumens to allow sequential administration of mapping and ablation injectants with minimal admixture. The mapping injectant consisted of a mixture of lidocaine, iohexal, and glycerin; the ablation injectant contained ethanol, iohexal, and glycerin. Infusion of the mapping injectant (1 cm3 over 3 or 5 seconds, n = 14) produced a stain on fluoroscopy and increased local capture threshold by 61%. No lesions resulted from mapping infusions. Infusion of the ethanol-containing injectant (n = 48) produced discrete lesions, with a mean volume ranging from 0.6 to 1.5 cm3. There was a direct relationship between infusion volume, infusion duration, and resultant lesion volume. Fibrosis in a region of healed myocardial infarction did not impair diffusion of the injectant or affect lesion dimensions. Microscopic analysis of chronic lesions showed a sharply demarcated border zone between fibrotic and normal myocardium.
Transcatheter subendocardial infusion can be used to reversibly impair local excitability and mark an injection site fluoroscopically. Subendocardial injection of ethanol can predictably ablate a large volume of ventricular myocardium. Additional study of this system in an arrhythmia model will help to define its potential for mapping and ablation of hypotensive ventricular tachycardia.
对于部分室性心动过速患者，射频能量导管消融是可行的。本研究的目的是评估一种使用经导管心内膜下注射来标测和消融心室心肌的技术。
使用尖端可弯曲的针状电极导管将试剂输送至心内膜靶点。该导管配备两个中央腔，以允许在最小程度混合的情况下依次注入标测和消融注射液。标测注射液由利多卡因、碘海醇和甘油混合而成；消融注射液包含乙醇、碘海醇和甘油。注入标测注射液（3或5秒内注入1立方厘米，n = 14）在荧光透视下产生染色，并使局部捕捉阈值提高61%。标测注入未导致形成病变。注入含乙醇的注射液（n = 48）产生了离散的病变，平均体积在0.6至1.5立方厘米之间。注入体积、注入持续时间与最终病变体积之间存在直接关系。愈合心肌梗死区域的纤维化并不影响注射液的扩散，也不影响病变大小。对慢性病变的显微镜分析显示，纤维化心肌与正常心肌之间有明显的边界区。
经导管心内膜下注射可用于可逆性地损害局部兴奋性，并在荧光透视下标记注射部位。心内膜下注射乙醇可预测地消融大量心室心肌。在心律失常模型中对该系统进行进一步研究将有助于确定其在标测和消融低血压性室性心动过速方面的潜力。
