RT-3DE在评价冠状动脉病变中的价值

目的：应用实时三维超声心动图（RT-3DE）评价左冠状动脉前降支供血的心肌节段的功能状态,探讨对其病变程度的判断价值.方法：103例行择期冠状动脉造影且存在前降支（LAD）狭窄病变的冠心病患者,分为50％≤狭窄＜75％组（A组）53例;狭窄≥75％组（B组）50例.选取同期冠状动脉造影正常者68例为对照组（N组）.均行RT-3DE检查,获取17节段容积-时间曲线,记录LAD支配的心肌节段的平均运动幅度（EA）、收缩期心室运动峰值时间（TS）、舒张末容积（sEDV）、收缩末容积（sESV）,计算节段射血分数（sEF）,并对部分参数进行ROC曲线分析及判别分析.结果：（1）B组左室前壁和前间隔中间段及心尖段EA值、前壁中间段和前间隔心尖段sEDV及sEF、前壁心尖段sESV及sEF均明显小于A组及N组（P＜0.05）,A组与N组之间均无明显差别（P＞0.05）.（2）ROC曲线分析显示前壁心尖段、中间段、前间隔心尖段sEF以及前壁和前间隔的中间段、心尖段EA均对冠脉狭窄有较高诊断价值,其中以前间隔心尖段EA和sEF更佳,前壁心尖段EA取值≤5.67时判断LAD狭窄≥75％的敏感度和特异度最佳,分别达91.27％和91.07％.（3）以前间隔心尖段sEF、EA为自变量建立的判别函数Y=0.461sEF＋0.672EA（P＜0.001）,判别临界值YLAD=0.438,对判断前降支狭窄程度≥75％的敏感性为88.00％,特异性为92.45％,总正确率为90.29％.结论：RT-3DE可准确、定量评价节段心肌运动幅度和收缩功能,推测相应供血冠脉的病变程度,选择适宜参数建立的判别函数可能成为预测冠脉介入治疗的指标.

Evaluation of coronary artery stenosis by using real-time three-dimensional echocardiography

Objective： To assess the clinical value of real-time three-dimensional echoeardiograghy （RT-3DE） in myocardial segments functional status supplied by left anterior descending artery （LAD） and to evaluate the value of diagnosis by coronary artery stenosis in patients with coronary atherosclerotic heart disease （CHD）. Methods：A hundred and three patients with LAD stenosis diagnosed by coronary angiography （CAG） were divided into group A （with coronary stenosis of LAD I〉 50% but〈75% ）and group B （with coronary stenosis of LAD 1〉75%）. Sixty eight cases without significant stenosis of coronary artery were selected as the control group （N group） in the same period. All subjects underwent RT-3DE. A series of regional left ventricular volume-Time Curves （VTC） were plotted. The parameters of left ventricular systolic function in regional cardiac ventricle related with LAD were acquired to calculate the areas under the ROC curve and the index cut-off value, after which the discriminant analysis was performed. Results： （1）Compared with group N and group A, the EA of middle section and apical segment of anterior and anterior septum wall, the sEDV and sEF of middle segment of anterior wall and apical segment of anterior septum wall, the sESV and sEF of apical segment of anterior wall in group B were significantly lower （P〈0.05）. But no significant difference was found between group A and group N in EA and sEF. （2）ROC curve analysis showed sEF of anterior wall apical segment, the middle segment and anterior septum apical segment, EA of middle section and apical segment of anterior and anterior septum wall had higher diagnostic value to coronary artery stenosis. The EA and sEF of apical segment of anterior septum wall could assess the degree of coronary artery stenosis better by ROC. When the EA of apical segment of anterior wall was no higher than 5.67, the optimal sensitivity and specificity were 91.27% and 91.07% respectively in assessing stcnosis of LAD no less than 75%. （3）sEF and EA of apical segment of anterior septum wall were taken as independent variables to establish discriminant function Y=0.461sEF＋0.672EA （P〈0.001）, with critical value YtAD being 0.438, total accuracy rate being 90.29%, and sensitivity and specificity, 92.45% and 88.00% respectively. Conclusion：RT-3DE can accurately and quantitatively assess segmental myocardial motion amplitude and systolic function to calculate the severity of coronary supply accordingly, and with appropriate parameters, discriminant function can be used to predict coronary intervention.