QTVI技术评价缺血后适应对缺血再灌注犬心功能的影响

Evaluation of the Effect of Ischemic Postconditioning on Ischemia-reperfused Canine Heart by Quantitative Tissue Velocity Imaging

目的探讨定量组织速度显像(QTVI)技术的应用价值及评价缺血后适应对缺血再灌注犬左室收缩功能影响。方法将21只杂种犬随机分3组:对照组(Con组,n=7):结扎左前降支(LAD)60 min,再灌注3 h;缺血预适应组(Pre-C组,n=7):结扎LAD 60 min前行缺血预适应(5 min结扎/5 min再灌注的4次循环);缺血后适应组(Post-C组,n=7):结扎LAD 60 min后,再灌注前行缺血后适应(30 s再灌/30 s再闭的3次循环)。应用QTVI观察犬缺血前,缺血60 min,再灌注60、120、180 min左室各壁收缩期峰值速度(Vs)、峰值位移(Ds),计算6个室壁Vs、Ds平均值(作为左室整体收缩功能)。直线解剖M型超声心动图获得短轴缩短率(FS),单平面Si mpson’s法测得左室射血分数(LVEF)。结果缺血60 min时各组Vs、Ds、LVEF、FS值均明显下降,组间没有显著差异;再灌注3 h后各组均有改善,Pre-C组、Post-C组明显高于Con组(P<0.05)。Ds、Vs与EF、FS均呈直线正相关(r分别为0.844、0.793、0.800、0.760,均P<0.05)。结论QTVI可较准确评价缺血再灌注犬心脏收缩功能变化;缺血后适应可减轻再灌注损伤对缺血心肌收缩功能影响。

Objective To evaluate the effect of ischemic-postconditioning on ischemia-reperfused canine myocardial function by quantitative tissue velocity imaging（QTVI）.Methods Twenty-one dogs were randomly divided into three groups,with 7 dogs in each group.In the control group（con group）,the left anterior descending artery（LAD） was reversibly occluded for 60 minutes,followed by 3-hour reperfusion.In the ischemic-preconditioning group（Pre-C group）,four cycles of 5-minute reperfusion and 5-minute reocclusion were performed before the prolonged LAD occlusion.In the ischemic-postconditioning group（Post-C group）,three cycles of 30-second reperfusion and 30-second reocclusion were performed 1 hour after LAD occlusion.The systolic peak velocity（Vs） and systolic peak displacement（Ds） were measured on anterior wall and inferior wall,anterior septum and post wall,post septum and lateral wall by QTVI.The left ventricular ejection fraction（LVEF） was measured using Simpson＇s method and the fractional shortening（FS） was measured by anatomical m-mode echocardiography.Results Vs,Ds,LVEF and FS decreased significantly at the end of ischemia in all groups.Compared with the control group,Vs,Ds,LVEF and FS increased 3 hours after reperfusion in Post-C group and Pre-C group（P〈0.05）,and Vs and Ds were correlated with LVEF and FS（r were 0.844、0.793、0.800、0.760,all P〈0.05）.Conclusion QTVI can evaluate systolic function exactly in myocardial ischemia-reperfused dogs,and Ischemic-postconditioning may have protective effects on ischemia-reperfused canine heart.