二维斑点追踪显像评价重度主动脉瓣狭窄患者左室壁心肌功能改变

Evaluation of left ventricular myocardial function in patients with severe aortic stenosis by two-dimensional speckle tracking imaging

目的应用二维斑点追踪显像（STI）技术评价单纯重度主动脉瓣狭窄（AS）患者左室收缩功能改变，并探讨其临床意义。方法左室射血分数（LVEF）≥50％的重度AS患者26例，健康志愿者28例。常规二维超声心动图获取左室二尖瓣、乳头肌、心尖水平短轴切面及心尖左心室长轴、四腔、两腔观的高帧频动态灰阶图像及STI图像，分析比较两组患者左室前间隔、前壁、侧壁、后壁、下壁及后间隔共18个节段收缩期的纵向应变（LS）、径向应变（RS）、环向应变（CS）及纵向应变率（LSr）、径向应变率（RSr）、环向应变率（CSr）。随机抽取AS组和对照组受检者各6例，由同一检查者及不同检查者分别测量LVEF和LS、RS值，检验测量重复性。结果①AS组与对照组的LVEF、左室舒张末期内径（LVEDD）、左室收缩末期内径（LVESD）、室壁中段缩短率（mwFS）比较，差异均无统计学意义（P〉0．05）。②AS组左室壁各节段收缩期的LS、RS、CS、LSr、RSr、CSr均明显低于正常组，差异有统计学意义（P〈0．05）。③同一检查者及不同检查者测量LVEF、LS、RS的重复性尚好。结论LVEF正常的重度AS患者左室壁应变及应变率减低，其心肌收缩功能受损。

Objective To evaluate left ventricular（LV） systolic function by two-dimensional speckle tracking imaging（2D-STI） in severe aortic stenosis（AS） patients. Methods Standard echocardiography and 2D-STI examinations were performed in a total of 54 subjects including 26 consecutive patients with severe AS with LV ejection fraction（LVEF） ~50% and 28 controls. 2D-STI including systolic longitudinal strain （LS） and strain rate（LSr） were assessed from the apical 4-chamber,3-ehamber and 2-chamber views,the circumferential strain（CS） and strain rate（CSr） ,radial strain（RS） and strain rate（RSr） were measured from the standard short axis views （averaging 6 segments per view）. The above parameters of AS groups were compared with those of normals. The repeatability of LVEF,LS and RS was evaluated in 6 AS patients and 6 normal volunteers selected at random from the investigation. Results （i） There was no significant difference between AS group and control group in LVEF, LV end-diastolic dimension（LVEDD）, LV end- systolic dimension （LVESD） and midwall fractional shortening （mwFS） （ P ~ 0.05）. （~） Significant differences were detected between the two groups. LS, RS, CS, LSr, RSr, and CSr were obviously decreased in AS group（ P〈0.05）. The repeatability of LVEF,LS and RS was good by consecutive measurement of identical and independent observers. Conclusions Despite the presence of normal LVEF, the LV systolic function is impaired in severe AS patients.