斑点追踪技术评价犬急性心肌梗死的心肌应变

目的 探讨二维超声心动图斑点追踪成像(STI)技术精确评价犬不同形式心肌收缩运动的意义及价值.方法 分离结扎11只健康杂种犬冠状动脉左前降支,造成犬急性心肌梗死,于梗死前后分别行超声心动图STI检查,应用观察实验犬急性心肌梗死前后左心室短轴径向应变(RS)、圆周应变(CS)及心尖长轴纵向应变(LS)的变化.结果 正常状态下左心室心肌各节段RS、CS差异无统计学意义(P>0.05),心肌CS高于LS(P<0.05),心尖位左心室心肌LS在基底段、中间段、心尖段依次递增,基底段最小,心尖段最大(P<0.05),心肌梗死后左心室中间段前壁、前间隔及心尖段前壁、前间壁和后间隔RS、CS及LS均明显低于梗死前(P<0.05).结论 STI可精确评价犬心肌不同形式的运动产生的应变.

Speckle tracking imaging technique evaluation of myocardial strain of dogs with acute myocardial infarction

Objective To discuss the significance and value of speckle tracking imaging (STI) technique for accurate evaluating different types myocardial systole. Methods Anterior interventricular branches of 11 healthy crossbreed dogs were separated and ligatured to establish acute myocardial infarction models. The short axle radial strain (RS), circumferential strain (CS) of ventricular sinister and long axle longitudinal (LS) of apex of experiment dogs were measured with STI technique before and after myocardial infarction. Results Before myocardial infarction, no statistical difference of RS, CS was detected among sections of left ventricle (P>0.05), and RS was greater than LS (P<0.05). When detector was at the apex of base, LS of middle, apex sections of left ventricle myocardium increased gradually (LS of base section was least and apex section was most) (P<0.05). RS, CS and LS of antetheca, forepart of interventricular septum of middle of left ventricle and antetheca, posterior and forepart septum of apex all became lower after myocardial infarction (P<0.05). Conclusion Strains caused by all types of myocardium action can be accurately evaluated with STI.