负荷DTI二尖瓣环舒张期波形改变对心肌缺血的提示意义

Changes of mitral annular dynamics during diastole response to dobutamine stress by Doppler tissue imaging: suggestion of myocardial ischemia

目的 了解负荷DTI二尖瓣环舒张期波形改变对心肌缺血的提示意义。方法 利用DTI观测 104例冠状动脉造影(CA)患者的二尖瓣环舒张期 4个位点的e波与a波的比值在多巴酚丁胺应用前后的变化,并与CA结果进行比较。结果 基础状态下DTI二尖瓣环 4个取样点的e/a均<1. 0时,冠心病的检出率较高,而二尖瓣环 4个取样点的e/a均≥1.0时的冠脉病变率最低(P<0. 01);负荷条件下原本各点e/aann≥1. 0的一些病例中出现部分取样点的e/aann<1. 0改变,其冠脉病变率增高或有增高的趋势(P<0. 05),而试验前后维持e/aann≥1. 0波形的病例的冠脉病变率有下降的趋势。结论 负荷剂量下不同位点的e/aann发生变化使得DTI以e/aann<1. 0为指标提示冠心病的准确度、灵敏度、特异度、阳性预测值和阴性预测值和以e/aann≥1. 0为指标排除冠心病的准确度、特异度、阳性预测值均有所提高。

Objective To understand the meaning of changes of mitral annular dynamics during diastole in diagnosing myocardial ischemia under the conditions of stress Doppler tissue imaging (DTI). Methods DTI studies including e/a ann ratio of 104 patients, who had undergone coronary arteriography, were obtained from each of 4 mitral annular sites, as follows: inferoseptal and lateral sites from the apical 4 chamber view, anterior and inferior sites from the apical 2 chamber view. According to the sites of e/a ann ≥1.0 or <1.0 at rest, 104 cases were divided into 5 groups: groupⅠ, in which e/a ann ≥1.0 was shown at all the 4 sites; group Ⅱ, e/a ann ≥1.0 at 3 of the sites; group Ⅲ, e/a ann ≥1.0 was detected at 2 sites; group Ⅳ, there was only one site with e/a ann ≥1.0; group Ⅴ, e/a ann ratios at all the sites were <1.0. Then, the groups above were further divided into several subgroups according to changes of the sites with e/a ann ≥1.0 after the stress DTI. Results The highest rate of coronary artery disease (CAD) was found in group Ⅴ at rest, while the lowest rate of CAD in group Ⅰ ( P <0.01). A tendency to have a high incidence of CAD was also noticed in the cases in which the e/a ann ratios changed from ≥1.0 into <1.0 after the tress echocardiography. However, no matter whatever happened the e/a ann ratios after the stress test, there still was a high incidence of CAD in group Ⅴ. Conclusion As changes of e/a ann ratios at partial sites in some cases of CAD happened during the stress test, analysis of these changes could improve the efficacy of stress DTI in diagnosing myocardial ischemia.