Radiofrequency ablation of ventricular outflow tract septum: a preliminary study in experimental canine / 介入放射学杂志

ABSTRACT

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.