射频消融犬心室流出道间隔初步实验研究

目的 初步探讨射频消融犬心室流出道间隔对左心室结构与功能的影响.方法 以健康实验犬为模型,射频消融心室流出道间隔处肌肉.术前经胸超声检测左心室流出道宽度、收缩期室间隔厚度和射血分数等指标,消融成功后即刻检测超声指标,术后1、3个月分别复查存活犬超声指标,作组织病理学检查.结果 10只实验犬中9只消融成功,1只术中发生室颤死亡;1只消融成功但麻醉过深,出现呼吸抑制死亡.手术即刻成功率为80％,8只术后存活至预定随访时间点.与术前相比,存活犬术后即刻、术后1个月、术后3个月左心室流出道宽度、收缩期室间隔厚度差异均有统计学意义(P＜0.05),射血分数差异均无统计学意义(P＞0.05);组织病理学检查可见明显改变;心电图、血压未见明显变化.结论 初步验证射频消融实验犬心室流出道间隔心肌具有一定的安全性和有效性,为进一步动物实验和临床试验提供了有用参数和实验依据.

Radiofrequency ablation of ventricular outflow tract septum: a preliminary study in experimental canine

Objective To investigate the effect of radiofrequency ablation (RFA) of ventricular outflow tract septum on the left ventricular structure and function in experimental canine.Methods Healthy experimental dogs were used for this study.RFA of the myocardium at ventricular outflow tract septum was performed.Before RFA,thoracic ultrasound examination was used to determine the width of left ventricular outflow tract,the systolic interventricular septum thickness,left ventricular ejection fraction,etc.The ultrasound examination was performed immediately after RFA to check the above indexes.Ultrasound examination was employed one and 3 months after RFA to record the above indexes of the survived dogs,and pathological examination was made.Results Among the 10 experimental dogs,successful RFA was achieved in 9,and one dog died of ventricular fibrillation.In one dog RFA was successfully accomplished,but it died of respiratory inhibition due to over-deep anesthesia.Immediate success rate of surgery was 80％,eight dogs survived to the scheduled follow-up time point.The width of left ventricular outflow tract and the systolic interventricular septum thickness determined immediately after RFA as well as one and three months after RFA in the survived dogs were significantly different from the preoperative data (P＜0.05).Histopathologically,striking microscopic changes could be observed.No obvious changes in ECG and blood pressure were seen.Conclusion The results of this study indicate that RFA of ventricular outflow tract septum in experimental dogs is safe and effective,which provides useful parameters and experimental basis for further animal experiments and clinical trials.