小剂量多巴酚丁胺超声心动图联合心肌声学造影对心肌梗死后存活心肌的诊断价值

Combined use of low - dose dobutamine echocardiography and myocardial contrast echocardiography to assess myocardial viability

目的 前瞻性评价小剂量多巴酚丁胺超声心动图（ＬＤＤＥ）联合心肌声学造影（ＭＣＥ）对心肌梗死后存活心肌的诊断价值。方法对２４例心肌梗死者进行静态ＭＣＥ、ＬＤＤＥ及３个月后静态超声心动图随访分析。ＭＣＥ和室壁运动均用１６段划分法进行目测半定量计分。心肌造影计分（ＭＣＳ）：回声均匀性增强为１分，回声低淡不均匀为０．５分，缺损为０分。室壁运动计分（ＷＭＳ）用常规计分法。结果随访时，运动改善的心肌节段中 ＭＣＳＩ分占４９． ４％、０． ５分占 ５０． ６％，对 ＬＤＤＥ均有反应；运动无改善的节段 ＭＣＳ ０． ５分占９． ５％，０分占 ９０． ５％，对 ＬＤＤＥ有反应者占１３．３％，无反应占８６．７％。预测存活心肌的敏感性、特异性及准确率分别为ＬＤＤＥ：８６％、８６．７％、８６．４％；ＭＣＥ：１００％、８９．７％、９４．６％；ＬＤＤＥ联合ＭＣＥ：８６．ｌ％、１００％、９４．０％。结论心肌微血管结构与功能的完善是心肌存活的基本条件。ＭＣＥ灌注正常和低灌注，且对多巴酚丁胺有反应的心肌有收缩力储备；而对多巴酚丁胺无反应的低灌注或无灌注心肌则多不能恢复收缩功能。ＬＤＤＥ联合ＭＣＥ能提高检测存活心肌的特异性及准确率。

Objective To predict prospectively viable myocedum with combined use of low - dose dobutamine echocardiography(LDDE) and myocardial contrast echocardiography(MCE). Methods 24 patients with myocedal infarction (MI) underwent resting MCE with intermittent harmonic, pulsed inversion imaging, LDDE and repeated resting echocardiography at 3 - month follow - up and regional function recovery was analyzed. Estimations of myocardial contrast score(MCS) and wall motion score (WMS) were made by visual analysis in 16 - segment model. MCS was graded as 1, homogeneous opacification; 0. 5,patchy pattern;0,no opacification. WMS was graded as 1 recovery;MCS 0. 5(9. 5% ) and 0(90.5% ) segments revealed irreversible dysfunction. Of these segments 13. 3% had positive and 86. 7% negative to LDDE at 3 - month follow - up. The sensitivity, specificity and accuracy in predicting viable myocardium were 86. 0%,86. 7% and 86. 4% by LDDE; 100%,89. 7% and 94. 6% by MCE;86. 1%,100% and 94. 0% by combination of LDDE and MCE respectively. Conclusions Microvascular anatomic and functional integrity is a fundamental requisite for ensuring viability after MI. Most of normal or decreased perfusion segments positively responded to LDDE demonstrate contractile reserve, while decreased or no perfusion segments with negative response to LDDE show irreversible dysfunction. The integration of LDDE with MCE can improve specificity and accuracy in detecting viable myocardium.