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目的应用二尖瓣血流脉冲多普勒(PWD)频谱及二维超声斑点追踪显像(STI)技术观察兔心肌梗死室壁瘤形成后左心室舒张和收缩功能的变化特点。方法以28只健康新西兰大白兔制作心肌梗死模型,饲养4周,23只兔成模并存活。以建模前超声检查作为对照组,术后4周复查超声并行病理学检查,根据有无室壁瘤形成分为心肌梗死组(n=11)和室壁瘤组(n=12)。测量左心室二维超声指标后,应用PWD分别测量各组二尖瓣的舒张早期血流速度(E)、舒张晚期血流速度(A);应用STI技术分别测量各组左心室短轴瓣环水平、心尖水平各节段的旋转角度、短轴瓣环水平圆周应变率(SrC)和径向应变率(SrR)的收缩期峰值应变率(SrC-S,SrR-S)、舒张早期峰值应变率(SrC-E,SrR-E)、舒张晚期峰值应变率(SrC-A,SrR-A),计算左心室整体扭转角度及舒张早期与舒张晚期峰值应变率之比(SrCe/SrCa,SrRe/SrRa)。结果与对照组比较,心肌梗死组和室壁瘤组左心室整体扭转角度及SrCe/SrCa、SrRe/SrRa均减小,以室壁瘤组更显著(P均<0.05);各组间E/A差异无统计学意义(P均>0.05)。结论兔心肌梗死室壁瘤形成后,E/A呈假性正常化,而短轴瓣环水平圆周和径向应变率、左心室整体扭转角度显著减小,左心室局部和整体舒张功能及收缩功能进一步恶化。
Objective To investigate the changes of left ventricular diastolic and systolic function after myocardial infarction aneurysm formation by using mitral flow pulsed Doppler (PWD) spectroscopy and two-dimensional speckle tracking imaging (STI). Methods Twenty-eight healthy New Zealand white rabbits were inflicted with myocardial infarction model. Four weeks later, 23 rabbits were sacrificed and survived. The pre-modeling ultrasound examination was taken as the control group. The pathological examination was performed 4 weeks after the operation and was divided into myocardial infarction group (n = 11) and ventricular aneurysm group (n = 12). After measuring the left ventricular two-dimensional ultrasound, PWD were used to measure the early diastolic flow velocity (E) and late diastolic flow velocity (A) in each group. The left ventricular short-axis annulus (SRC-S, SrR-S), peak early diastolic strain (SBR), peak systolic strain rate (SrC-E, SrR-E) and peak late diastolic strain rate (SrC-A, SrR-A) were calculated to calculate the ratio of total left ventricular torsional angle and the ratio of peak strain rate of early diastolic to late diastolic (SrCe / SrRa). Results Compared with the control group, the left ventricular total torsion angle and SrCe / SrCa, SrRe / SrRa in myocardial infarction group and aneurysm group decreased significantly (P <0.05), and E / A The difference was not statistically significant (P> 0.05). Conclusion E / A was normalized after the formation of ventricular aneurysm in rabbit myocardium, and the horizontal circumference and radial strain rate of short axis annulus were significantly reduced, while the global left ventricular torsion angle was significantly reduced. Local and global left ventricular diastolic function and systolic Function further deterioration.