肾交感神经消融抑制心力衰竭犬左心室机械不同步性的实验研究

Renal sympathetic denervation inhibites the development of left ventricular mechanical dyssynchrony during the progression of heart failure in dogs

目的 观察肾交感神经射频消融是否可以干预心力衰竭（心衰）犬左心室不同步性的进展.方法 19只比格犬随机分为3组：假手术组6只,对照组7只和消融组6只.假手术组犬装起搏器,但不开启;对照组装好起搏器后开始快速右室起搏3周;消融组先对双侧肾交感神经消融,同时植入起搏器,开启快速右室起搏3周.应用超声二维斑点追踪技术评价左室应变和左室不同步性.左室长轴方向不同步性通过心尖二腔和四腔心切面各个节段的应变达峰时间标准差来评价,径向和圆周方向的左室不同步性通过短轴方向上各个节段的应变达峰时间标准差来评价.测量左室收缩压（LVSP）和左室舒张末压（LVEDP）,用组织学方法来分析左室心肌纤维基质变化.结果 3周后,对照组和消融组犬左室舒张末期容积较假手术组大;但消融组犬左室射血分数高于对照组（P＜0.001）.长径方向、圆周方向和径向方向上左室收缩期应变消融组均高于对照组（P ＜0.001）,长径方向、圆周方向和径向方向上左室不同步性水平消融组低于对照组（P＜0.001）.与对照组相比,消融组犬左室舒张末压更小,心肌组织纤维化程度更低.结论 肾交感神经消融可以抑制心衰犬左室不同步性进展.

Objective To investigate whether transcatheter renal sympathetic denervation （RSD） by radiofrequency ablation interfere with the development of left ventricular （LV） mechanical dyssynchrony during the progression of heart failure （HF）.Methods Nineteen beagles were randomly divided into sham-operated group （six dogs）,control group （seven dogs）,and RSD group （six dogs）.Sham-operated group were implanted with pacemakers without pacing;Control group were implanted with pacemakers and underwent 3 weeks of rapid right ventricular pacing;and RSD group underwent catheter-based RSD bilaterally and were simultaneously implanted with pacemakers.LV dyssynchrony was analyzed via 2D speckle-tracking strain echocardiography to evaluate LV function.Longitudinal dyssynchrony was determined as the standard deviation for time-to-peak speckle-tracking strain on apical 4-and 2-chamber views.Radial and circumferential dyssynchrony was determined as the standard deviation for time-to-peak speckle-tracking strain in mid-and base-LV short-axis views.LV systolic pressure （LVSP） and LV end-diastolic pressure （LVEDP） were measured.The LV interstitial fibrosis was determined by histological analysis.Results After 3 weeks,all of the dogs in both the control and RSD groups showed greater LV end-diastolic volume compared with the sham-operated group;however,the dogs in the RSD group had a higher LV ejection fraction （LVEF） than the dogs in the control group （P 〈0.001）.The LV systolic strains were higher in the RSD group than in the control group （P 〈0.001 for longitudinal,circumferential and radial strain,respectively）.The levels of LV dyssynchrony were lower in the RSD group than in the control group （P 〈 0.001 for longitudinal,circumferential and radial dyssynchrony,respectively）.Compared with control group,RSD group had lower LV end-diastolic pressures and less fibrous tissue.Conclusions RSD inhibites the development of left ventricular mechanical dyssynchrony during the progression of heart failure in dogs.