组织多普勒技术定量评价心肌梗死患者左室壁的收缩后收缩

目的：讨论急性与陈旧性心肌梗死（MI）患者左心室收缩后收缩（PSS）出现的比例和峰值，以及与左心室节段功能的关系。方法：入选（MI）患者42例，其中急性（MI）、陈旧性（MI）和正常对照组各14例（A，B，C组）。运用GEvivid 7彩色超声仪采集惠者心尖3个切面的超声图像，并用Q-analyse分析软件测量左心室12节段的收缩期峰值速度（Sm），收缩后收缩峰值速度（PSS），舒张早期、晚期峰值速度（Em，Am），收缩期峰值位移（Ds）和收缩期峰值应变力（εs），用双平面Simposon法测量患者的EF值。结果：（1）MI后，PSS节段占总节段数的比例较正常增加，且A组比B组的增加更明显（P〈0．01）；PSS峰值较正常升高，且A组比B组升高更显著（P〈0．01）。（2）A、B两组的Sm，Em，Am，Ds和如均明显低于C组（P〈0．01），但A、B两组间除了Em外（P〈0．01），其余参数无显著差异（P〉0．05）。（3）C组左心室基底段的平均PSS与EE值正相关（P〈20．05），而A、B两组平均PSS与EF值呈现负相关趋势。结论：组织多普勒技术评价（MI）患者左心室PSS的比例和峰值，可以反映心肌的缺血、存活和节段功能的细微变化，是一种无创、快捷、定量的客观指标。     

斑点追踪显像技术定量评价心肌梗死局部室壁运动异常

目的 应用超声斑点追踪显像技术测量心肌梗死患者各节段室壁的二维应变,探讨其诊断局部室壁运动异常的临床应用价值.方法 30例正常人、21例前壁心肌梗死患者和15例下壁心肌梗死患者分别记录心尖位两腔观及左室乳头肌水平短轴观的高帧频图像,应用二维应变软件测量各节段的纵向应变(LS)、径向收缩期峰值速度(Vs)、局部短轴缩短分数(RFS)、径向应变(RS).结果 与正常组相比,心肌梗死各组心尖位节段LS、Vs、RFS、RS明显减低(P<0.05).心肌梗死组间比较,部分节段的LS、Vs、RFS、RS存在明显差异(P<0.05).结论 超声斑点追踪显像技术可准确评价节段性室壁运动异常,为临床评价心肌梗死患者左室收缩功能提供了无创性新方法.     

应变率成像评价陈旧性心肌梗死患者左心房收缩功能

目的 探讨应变率成像评价陈旧性心肌梗死患者左心房收缩功能的价值.方法 对30例陈旧性心肌梗死患者(心梗组)和25例正常人(对照组),应用应变率成像测量左心房侧壁及房间隔心肌运动速度;分析心梗组与对照组心房侧壁及房间隔收缩功能的改变.结果 ①与对照组相比,心梗组左心房心肌运动速度在心室收缩期和心室舒张早期减低,而在心室舒张晚期增高,差异有统计学意义(P<0.05).②与对照组相比,心梗组左房被动射血量指数减少,主动射血量指数增加,差异有统计学意义(P<0.001).结论 应变率成像可以准确评价陈旧性心肌梗死患者左房功能.     

Effect of Transmural Extent of the Simulated Infarction in a Left Ventricular Model on Displacement and Strain Distribution Estimated from Synthetic Ultrasonic Data

The identification of a sub-endocardial infarction is of major interest in cardiology. This study evaluates the sensitivity of selected measures to the thickness of such an infarction. Synthetic ultrasonic data (long-axis view) of left ventricular models with inclusions were generated using Field II and meshes obtained from finite-element simulations, which also provided the reference for the estimates obtained from ultrasonic data. The displacements, the first and second component of the principal strain (ε₁ and ε₂), and several measures derived from these quantities were estimated. All estimates, except for the poorly estimated ε₂, exhibited sensitivity to the presence and transmurality of the inclusion. The most sensitive was the gradient of the averaged transmural profiles of ε₁, and ε₁ averaged over the area corresponding to the transmural inclusion. The inflection point of the ε₁ profile shifted toward the outer wall with increasing thickness of the non-transmural inclusion.     

Echocardiographic Strain Analysis for the Early Detection of Myocardial Structural Abnormality and Initiation of Drug Therapy in a Mouse Model of Dilated Cardiomyopathy

This study aimed to evaluate the role of echocardiography-based strain analysis in the early diagnosis and guidance for management of dilated cardiomyopathy (DCM). Muscular dystrophy mice (which spontaneously develop DCM) and control (C57 BL/6 J) mice were sequentially evaluated by ultrasound biomicroscopy, conventional left ventricle (LV) measurement, two-dimensional (2-D) strain analysis and myocardial histologic analysis for 12 consecutive months. Significant alternation of LV remodeling and dysfunction could be detected by conventional echocardiography after 9 mo, by strain analysis after 5 mo and by histologic analysis after 4 mo. The global longitudinal systolic peak strain (PK) was the most sensitive strain marker for early detection of myocardial structural abnormality in the subclinical stage. Moreover, losartan administration before the PK decrease was associated with significantly preserved LV function. These results suggest that myocardial strain analysis (particularly longitudinal PK) is sensitive for the early detection of LV dysfunction in mice with dilated cardiomyopathy.