Vincent G M, Fox J, Benedick B A, Hunter J, Dixon J A
Nora Eccles Harrison Cardiovascular Research, University of Utah School of Medicine, Salt Lake City.
Lasers Surg Med. 1987;7(5):421-5. doi: 10.1002/lsm.1900070508.
Catheter-directed laser injury of the left ventricular endocardium for ablation of ventricular tachycardia was studied in a canine model of simulated ventricular tachycardia. Bipolar plunge electrodes were placed at thoracotomy into the left ventricular endocardium in nine anesthetized dogs. Ventricular tachycardia was simulated by pacing at 200 beats per minute. After four days of recovery, catheter-directed neodymium:yttrium-aluminum-garnet laser injury was produced at the site of earliest recorded electrical activation during pacing tachycardia as detected by endocardial catheter mapping. Immediately after laser injury and again five days after injury, pacing tachycardia was attempted. Failure to pace after laser injury was defined as successful arrhythmia ablation. In 3/9 (33%) experiments, the laser-injured tissue surrounded the tachycardia source (pacing wires), and pacing-simulated ventricular tachycardia was prevented. When the laser injury did not involve the tachycardia source, 6/9 animals, due to limitations of the mapping system, pacing was not prevented. One animal developed sustained ventricular tachycardia during laser injury, with conversion to sinus rhythm by lidocaine. One animal, without recognized ventricular arrhythmia, died five days after laser injury. No unusual findings were noted at autopsy. These preliminary data suggest that catheter-directed laser-induced injury can ablate arrhythmia sources. Further studies are indicated in a more physiologic model, and the safety and risks of the procedure need further evaluation.
在模拟室性心动过速的犬模型中，研究了经导管激光损伤左心室心内膜以消融室性心动过速。在9只麻醉犬的开胸手术中，将双极插入电极置于左心室心内膜。以每分钟200次的频率起搏来模拟室性心动过速。恢复四天后，通过心内膜导管标测检测到在起搏性心动过速期间最早记录到电激动的部位进行经导管钕：钇铝石榴石激光损伤。在激光损伤后立即以及损伤后五天再次尝试起搏性心动过速。激光损伤后无法起搏被定义为心律失常消融成功。在3/9（33%）的实验中，激光损伤的组织包围了心动过速源（起搏导线），并预防了起搏模拟的室性心动过速。当激光损伤未累及心动过速源时，由于标测系统的局限性，6/9的动物未预防起搏。一只动物在激光损伤期间发生持续性室性心动过速，通过利多卡因转为窦性心律。一只动物在未识别出室性心律失常的情况下，在激光损伤后五天死亡。尸检未发现异常。这些初步数据表明，经导管激光诱导的损伤可以消融心律失常源。需要在更生理的模型中进行进一步研究，并且该操作的安全性和风险需要进一步评估。
