组织多普勒腺苷负荷超声心动图定量评估心肌缺血的应用

Quantitative evaluation of ischemic myocardium by adenosine tissue Doppler stress echocardiography

目的评价定量腺苷负荷超声心动图技术诊断冠心病的准确性。方法40例患者行常规剂量（140μg·kg^-1·min^-1持续6min静脉滴注）腺苷负荷超声心动图试验以评估心肌缺血。基于常规二维图像之上的组织多普勒成像采集基线状态和药物负荷状态下的心肌运动图像（美国GEVIVID7超声诊断仪），在ECHOPAC软件上进行后处理分析测量16节段心肌运动速度、应变、应变率。结果以冠状动脉造影或CT冠状动脉成像为标准，共有缺血节段159个节段，非缺血节段465个。腺苷负荷峰值后，除缺血心肌的舒张早期应变（Se）无明显变化外，缺血心肌和非缺血心肌的收缩期速度（Sm）、舒张早期速度（Em）、舒张晚期速度（Am）和收缩期应变（Smax）以及收缩期应变率（SRs）、舒张早期应变率（SRe）、舒张晚期应变率（SRa），以及非缺血心肌的舒张早期应变（Se）均明显增加（P〈0．05）。缺血心肌的基线Sm和Em均显著低于非缺血心肌[分别为（3．16±1．20）cm/s和（4．03±1．27）cm／s，P〈0．01；（3．75±1．67）cm／s和（4．66±1．70）cm／s，P〈0．05]，峰值负荷下，两组间Sm和Em差异更加显著[分别为（3．98±1．63）cm／s和（5．07±1．52）cm／s；（4．51±2．32）cm／s和（6．52±2．56）cm／s；均P〈0．01]；缺血心肌的收缩期应变（Smax）和舒张早期应变（Se）均明显低于非缺血心肌（分别为16．91％±3．35％和19．56％±5．47％，P〈0．01；9．53％±2．89％和13．06％±4．63％，P〈0．001）。操作者工作特性（ROC）曲线所得曲线下面积以负荷峰值的Se最大（曲线下面积=0．740，敏感性为67％，特异性为83％）。结论组织多普勒负荷超声心动图参数可定量评估心肌缺血，是临床非创伤性诊断冠心病准确可靠的方法。

Objective To evaluate the value of adenosine tissue Doppler stress echocardiography on ischemic myocardium. Methods Routine dosage （ 140 μg·kg^-1·min^-1 IV for 6 min） adenosine stress echocardiography was performed on 40 patients with chest pain for diagnosis of coronary artery disease （CAD）. The images of left ventricular myocardial motion were acquired by tissue Doppler imaging （TDI） based on traditional 2D stress echocardiography before and 3 rain, 6 min after adenosine stress （ GE Vivid 7, USA）. The myocardial velocity, strain and strain rate in 16 segments were offline measured and analyzed on ECHOPAC software. The results were compared with that of coronary angiography （CAG）. Results CAG identified 18 CAD and 22 non-CAD patients with 159 ischemic segments and 465 non-ischemic segments. Adenosine significantly increased the systolic velocity （Sm）, early diastolic velocity （Em）, late diastolic velocity （Am）, peak systolic strain （Smax）, systolic strain rate （SRs）, early diastolic strain rate （SRe） and late diastolic strain rate （SRa） both ischemic and non-ischemic segments （all P 〈0. 05）. The baseline Sm and Em in ischemic segments were significant lower than non-ischemic segments [ （3. 16 ± 1.20） cm/s vs （4. 03 ±1.27） cm/s, P 〈 0. 01 ; （3.75±1.67 ） cm/s vs （4. 66 ± 1.70） cm/s, P 〈 0. 05 ]. At peak stress the differences in Sm and Em were more significant [ （3.98 ± 1.63） cm/s vs （5.07 ± 1.52） cm/s; （4.51 ±2.32） cm/s vs （6.52 ±2.56） cm/s; P〈0.01]. The reductions on Smax and Se were more significant in isehemie segments compared those in non-ischemic segments （16. 91%± 3.35% vs 19. 56% ± 5.47%, P 〈 0. 01 and 9. 53% ± 2. 89% vs 13.06% ± 4. 63%, P 〈 0. 001 ）. The biggest area under curve （AUC） in peak stress was seen in Se by ROC curve analysis （AUC =0. 740, with sensitivity 67% and specificity 83% ）. Conclusion Parameters derived from TDI offer reliable and accurate information on ischemic myocardium during adenosine stress echocardiography.