常规超声心动图结合彩色室壁动态技术评价猪急性心肌梗死模型

摘要

目的 应用常规超声心动图结合彩色室壁动态(color kinesis,CK)技术对猪急性心肌梗死(acute myocardium infarction,AMI)左心室结构和整体功能进行评价.方法 采用经冠状动脉丝线堵塞法制作小型猪AMI动物模型,于术前、术后1 d应用M型超声测量左室收缩与舒张末期内径(LVEDs,LVEDd);Simpson单平面法检测左室射血分数(EF);脉冲多普勒成像技术测量二尖瓣口舒张早期血流峰值速度(E)、舒张晚期血流峰值速度(A)并计算E/A;组织多普勒成像(Doppler tissue imaging,DTI)技术测量二尖瓣环与侧壁交界处心肌组织收缩期运动速度峰值(Sm)、舒张早期运动速度峰值(Em)、舒张晚期运动速度峰值(Am)并计算Em/Am;CK检测左心室16节段室壁运动幅度(Dis).根据健康小型猪术前左心室各节段Dis的95%可信区间下限值(5 mm)判定室壁运动异常节段(心肌缺血/梗死节段),并将CK确定的异常节段与组织病理学结果进行对照分析.结果 与术前相比,术后LVEDs增大,EF降低,Sm降低,差异均有统计学意义(P<0.05).与组织病理学结果对照分析,CK对心肌缺血/梗死节段判定的敏感性为86.67%,特异性为90.12%,准确性为89.58%.结论 常规超声心动图结合CK能对猪AMI后结构及整体心功能进行定量分析.%Objective To assess the structure and the global function of left ventricular after acute myocardium infarction(AMI) in pigs by conventional echocardiography and color kinesis(CK). Methods The coronary arteries of pigs were obstructed by thread to prepare model AMI. Before and one day after the procedure, left ventricular end systolic diameter(LVEDs) and left ventricular end diastolic diameter(LVEDd) were detected and left ventricular ejection fraction(EF) was measured with Simpson single-plane methods. Pulsed wave Doppler imaging was used to measure the early-diastolic and late-diastolic maximal velocity of mitral flow (E, A) and calculate the E/A ratio. Doppler tissue imaging(DTI) was used to obtain systolic, early-diastolic and late-diastolic peak velocity of the mitral annulus lateral site (Sm, Em, Am respectively) and calculate the Em/Am ratio. CK was used to detect the wall motion displacement (Dis) of LV 16 segments. The lower limit value (5 mm) of 95％ confidence interval of the difference about Dis in healthy pigs was regarded as the standard for diagnosing abnormal segments (infarcted segments). The segments diagnosed by CK as infarcted ones were compared with the results of histopathological examination. Results Compared with the parameters measured before the operation, LVEDs expanded, EF decreased and Sm decreased after the operation. There were statistically significant differences between each two measurements(P＜0. 05). Compared with the histopathological results, the detecting sensibility, specificity and accuracy of the diagnosis of infarcted segments by CK were 86.67 ％, 90. 12 ％ and 89. 58％ respectively. Conclusions Conventional echocardiography and CK can quantitatively assess the structure and the global function of left ventricular after AMI in pigs.