目的 应用斑点追踪技术评价室壁运动正常的心肌缺血患者左室心肌纵向应变，探讨二维纵向应变检测心肌缺血的临床价值。方法 44例经冠状动脉造影证实的冠心病患者和28例对照者接受二维超声检查，用二维应变软件分析心尖长轴观、心尖两腔和四腔观的图像，获取左室各节段心肌纵向应变、18节段心肌纵向应变均值(SL18)和12节段（除外6个心尖节段）纵向应变均值(SL12)。结果 冠心病组缺血节段的纵向应变及整体纵向应变均较正常对照组明显减低;无论正常组还是冠心病组，心尖节段纵向应变均明显高于基底段和中间段，SL18与SL12之间差异有统计学意义;ROC曲线表明SL18诊断心肌缺血的截断值为-18.8％，敏感性为80.2％，特异性为74.1％；SL12诊断心肌缺血的截断值为-17.8％，敏感性为81.7％，特异性为85.6％。SL12诊断心肌缺血的敏感性与SL18接近，但特异性较SL18明显增高。结论 二维纵向应变均值能较敏感地发现心肌缺血，12节段的二维纵向应变均值较18节段能更准确地评价心肌缺血。%Objective To assess left ventricular(LV) longitudinal strain in patients with coronary heart disease by two-dimensional speckle tracking imaging (2DSTI),and to explore the clinical value of 2D longitudinal strain in detecting myocardial ischemia. Methods Forty-four patients with coronary heart disease (CHD group) and 28 age-matched subjects (control group) were enrolled into this study. The two-dimensional data were obtained in apical 4-chamble, 2-chamber and long axis view. And the longitudinal strains of every segments, the average longitudinal strain of LV 18 segments (SL18), the average longitudinal strain of 12 segments (SL12,excluded the 6 apical segments) were analyzed. Results In the patients with CHD, the longitudinal strain of ischemia segments and the global LV longitudinal strain were significantly decreased than that of the control subjects. Both in patients with CHD and in control subjects,the longitudinal strains in apical segments were higher than that of middle and basal segments. There was significant difference between SL18 and SL12 ( P=0.027 in CHD group and P =0.003 in control group).Receiver operating curve (ROC) analysis demonstrated that the cutoff point of SL18 to detect myocardial ischemia was - 18.8％ (sensitivity 80.2％ and specificity 74.1％ ) ,and the cutoff point of SL12 to detect myocardial ischemia was - 17.8％ ( sensitivity 81.7％ and specificity 85.6％ ). Conclusions 2D longitudinal strain was sensitive to detect myocardial ischemia, SL12 was better than SL18 in detecting myocardial ischemia. 2DSTI might be useful for identifying patients with severe CHD.
展开▼
