激光心房迷宫术治疗心房纤颤的研究

Study of the maze procedure treatment for atrial fibrillation with Nd:YAG laser on canines

目的 探讨用Nd:YAG激光照射热凝代替手术切开 ,行改良的迷宫术Ⅲ治疗心房纤颤(简称房颤 )。方法 8条犬右房远端安放起搏电极行单纯心房Burst刺激 ,或在静滴氯化乙酰胆碱每分钟 1μg/kg体重的基础上加用心房Burst刺激诱发房颤 ,建立持续性房颤模型后以改良的激光心房迷宫术Ⅲ治疗。术后以同样条件刺激 ,观察是否还可引出房颤。结果 8条犬在激光心房迷宫术后以同样条件刺激均不能再诱发出房颤 ,平均心跳停时间为 2 4min。结论 Nd:YAG激光照射心房肌 ,可使心房肌达全层坏死失去电生理传导功能 ,可代替手术切开法行迷宫术治疗。

Objective To modify maze procedure using Nd:YAG laser thermal coagulation in stead of incision so as to simplify the operation,shorten the operation time and reduce postoperative complications.Methods Right thoractomy was performed on 8 dogs and pacing electrode was placed in the distal part of the right atrium near sinoatrial node.Single Burst pacing or Burst pacing on the basis of intravenous acetylcholine chloride infusion to establish the model of persistant atrial fibrillation was performed. It was considered successful when the criteria were met:atrial fibrillation was induced totally by 5 Burst pacing and at least ≥3 episodes of atrial fibrillation for each lasting ≥3 min. Modified laser maze procedure under cardiopulmonary bypass was performed on the 8 dogs in which atrial fibrillation has been successfully induced. The same type of stimulation was used to observe whether it can induce atrial fibrillation postoperatively.Results Persistant atrial fibrillation was successfully induced in 8 dogs in which single Burst pacing or Burst pacing with acetylcholine chloride infusion was applied. After laser maze procedure Ⅲ modified,atrial fibrillation could not be induced in the same 8 dogs. Conclusions A certain amount of laser energy can cause transmural necrosis and lose electrophysiological conduction function in the atrial myocardium. Nd:YAG laser thermal coagulation can be used to replace incision in the treatment of atrial fibrillation with maze procedure.