二维超声斑点追踪技术评价正常人左室短轴收缩期圆周应变的变化规律

Measurements of two dimensional circumferetial strain in healthy subjects by echocardiography speckle tracking imaging

目的应用二维超声斑点追踪成像(2D-STI)技术,评价正常人左室短轴收缩期圆周应变。方法 50例健康人,男20例,女30例,平均年龄(41.1±20.1)岁;采集左室短轴二尖瓣、乳头肌及心尖水平二维灰阶图像,使用Qlab8.1工作站进行脱机分析,系统自动将左室短轴心肌分为前间隔(AS)、前壁(AW)、侧壁(LW)、后壁(PW)、下壁(IW)、后间隔(PS)6节段,共计18节段,将左室壁心肌等分心内膜下层、心外膜下层心肌及整体心肌为感兴趣区,应用二维超声斑点追踪成像技术分析感兴趣区收缩期圆周峰值应变。结果正常人心内膜下层心肌各节段收缩期圆周峰值应变均高于心外膜下层心肌峰值应变(P<0.05),而且收缩期圆周应变整体心肌同一水平各节段间存在差异,特别是前间隔、后间隔与其它各壁差异有统计学意义(P<0.01)。结论二维超声斑点追踪成像技术不受声束角度的限制,可以准确评价左室心肌各节段收缩期圆周应变,为测定左室收缩功能提供更新的方法。

Objective To evaluate left ventricular systolic circumferental strain（CS）by echocardiography speckle tracking in health subjects.Methods 50 healthy subjects（male 20,female 30）with mean age of（41.1±20.1）years old were studied.Two-dimensional（2D）images of three consecutive cardiac cycles were recorded from left ventricular short-axis views at the levels of mitral annulus,papillary muscle and apex.2D images were transferred to Qlab8 and One workstation for offline strain analysis.The peak systolic of CS was 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（P0.05）.In the same level,the CS values of anteroseptal and posterior segment showed higher than those of the other segment（P0.01）.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,it has the potency to be used clinically in evaluation of LV regional myocardial systolic function is a new method of in diagnosis of cardiac diseases.