斑点追踪技术在急性ST段抬高心肌梗死多层次旋转和扭转运动中的应用

Assessment of rotation and torsion in endocardial and epicardial layers of acute ST evaluation myocardial infarction with speckle tracking technology

目的探讨急性ST段抬高心肌梗死（ASTEMI）心内膜、外膜的旋转和扭转运动规律。方法选择初发ASTEMI患者55例（ASTEMI组）、左心功能衰竭（LHF）25例（LHF组）、正常对照者35例（对照组），应用二维斑点追踪技术测定左室短轴切面基底水平和心尖水平心内、外膜及整体的收缩期最大旋转角度，同时计算整个左室心内、外膜及整体的扭转角度，并比较分析不同肌钙蛋白Ⅰ（TnⅠ）水平ASTEMI患者的扭转参数。结果与正常组比较，ASTEMI组基底水平、心尖水平心内膜旋转角度及左室心内膜、整体扭转角度均明显减小（均P〈0．05），左室心外膜的扭转角度无明显差异（P〉0．05）；与LHF组比较，ASTEMI组基底水平、心尖水平心内外膜和整体旋转角度以及左室心内、外膜和整体扭转角度均发生明显改变（均P〈0．01）。与TnⅠ〈1ng／ml者比较．TnⅠ〉1ng／ml者EDVI、ESVI明显增大（均P〈0．01）。LVEF、EpTor、GTor明显减小（均P〈0．01），而EnTor却无明显差异（P〉0．05）。结论ASTEMI早期心内膜旋转和扭转运动先发生损害，有透壁性心肌损害时才出现心外膜扭转运动减低，ASTEMI组左室整体心功能损害较轻可能与心外膜扭转运动未受明显损害有关。

Objective To assess the rotation and torsion in endocardial and epicardial layers of acute ST evaluation myocardial infarction （ASTEMI）with two-dimensional speckle tracking echocardiography. Methods Fifty five patients with first ASTEMI, 25 patients with left heart failure （LHF）and 35 normal subjects were enrolred in the study. The peak systolic rotation of endocardial layer, epicardial layer and global level in left ventricular basal and apical level were measured using two-dimensional speckle tracking technology, and meanwhile the torsion in different layers was calculated, Troponin Ⅰ （Tn Ⅰ） levels were mea- sured in ASTEMI patients. Results The endocardial rotation in basal and apical levels and the left ventricular endocardial torsion, global torsion in ASTEMI group were significantly reduced compared with normal group（P〈0.05）, while epicardial torsion was not statistically reduced （P 〉0.05）. The rotation and torsion in all layers were higher in ASTEMI than in LHF （P〈0.01）. Epicardial and global torsion in ASTEMI patients with Tn Ⅰ 〉1ng/ml were significantly reduced （P〈0.01）,but endocardial torsion was not significantly reduced （P 〉0.05）,compared with those with Tn Ⅰ 〈1ng/ml. Conclusion The rotation and twist in endocardial layers are first damaged in ASTEMI, and transmural myocardial damage may result in a reduction in epicardial twist. Left ventricular function of ASTEMI is damaged mildly, which may be related to the relatively normal epicarclial twist.