家兔挤压伤后心脏节段旋转功能评价的实验研究

Experimental study on cardiac segmental rotation function of rabbits after crush injury

目的应用超声斑点追踪技术评价家兔挤压伤后的心脏收缩期节段旋转功能,评估挤压伤后心肌继发受损的情况。方法 42只新西兰家兔按标准制作挤压伤模型,随机分为对照组,解压即刻,解压后6、12、24、48、72 h共7组,每组6只,分别检测挤压前及解压后不同时间段左室收缩期节段旋转功能等情况。结果左室感兴趣区域的收缩期节段旋转功能在解压后12～24 h降至最低(P<0.01),72 h后逐渐恢复并相对稳定在一定水平。结论挤压伤后由于缺血再灌注等多种因素可导致心肌正性变力及变时效应减低,以致心肌纤维收缩性能及节段旋转功能明显降低,伤后12～24 h为心肌受损达峰时间段。

Objective To evaluate the cardiac segmental rotation function of rabbits during the paradoxical expansion after crush injury by speckle tracking echocardiography（STE） ,and to assess myocardial secondary damages after the crush injury. Methods Forty - two New Zealand rabbits were made into animal models of crush injury and were randomly divided into seven groups, i. e. control group, immediate decompression group and groups in 6,12,24,48 and 72 h after the decompression（in each group n = 6）. The segmental rotation function during left ventricle contraction was detected at different times before the crush and after the decompression. Results The segmental rotation function during the contraction in the region of interest （ROI） decreased to the lowest 12 - 24 h after the decompression（P 〈 0.01 ）, and it gradually recovered and became stable at a certain level 72 h after the decompression. Conclusion After the crush injury, various factors such as ischemia and reperfusian may cause positive inotropism in myocardium and the decrease of chronotropic effects,which results in the obvious decrease of myocardial contractility and segmental rotation function. The myocardial damage reaches to the peak in 12 - 24 h after the crush iniurv.