超声斑点追踪成像技术评价正常人左室心肌周向收缩功能

目的 应用超声斑点追踪成像(STI)评价正常人左室心肌周向收缩功能.方法 35例正常人取二尖瓣、乳头肌及心尖水平短轴连续3个心动周期的二维灰阶图像,使用Qlab 6.0工作站进行脱机分析,系统自动将左室短轴分为前间隔、前壁、侧壁、后壁,下壁、室间隔6段,共计18个节段,将左室壁等分为心内膜下感兴趣区及心外膜下感兴趣区,应用STI技术分析感兴趣区的周向收缩期峰值应变.结果 心内膜层心肌各室壁节段周向收缩期峰值应变均高于心外膜层心肌(P<0.05),尤以前间隔和后壁节段差异更为显著(P<0.01).结论 超声斑点追踪成像技术不受声束角度的限制,可用于评价左室局部心肌的周向收缩功能.

Evaluation of circumferential systolic function of left ventricle using speckle tracking imaging in healthy subjects

Objective To evaluate the left ventricular circumferential systolic function by speckle tracking imaging (STI) in healthy subjects. Methods Study population consisted of 35 healthy subjects (male 20, female 15) with mean age of (38.4±15.4) years. High frame rate two-dimensional (2D) images of three consecutive cardiac cycles were recorded from the left ventricular short-axis views at the levels of mitral annulus, papillary muscle and apex. 2D images were transferred to Qlab 6.0 workstation for offline strain analysis. The peak systolic circumferential strain (CS) were measured in the left ventricular short-axis views from 18 standard segments in the inner and outer layers of myocardium using two-dimensional strain software. Results The CS values of the inner layers showed higher than those of the outer layers at 18 segments (P<0.05), especially in anteroseptal and posterior (P<0.01). In the same level, the CS values of anteroseptal and inferior wall segment showed higher than those of the other segments. Conclusion Speckle tracking imaging technique is independent of insonation angle for assessing myocardial strain, illustrates a difference in CS between the inner and outer layers, has the potential to be used clinically in evaluation of LV regional myocardial systolic function.