经静脉实时心肌造影超声心动图评估心肌梗死后存活心肌

Evaluation of myocardial viability after myocardial infarction with intravenous real-time myocardial contrast echocardiography

目的探讨经静脉实时心肌造影超声心动图（RT-MCE）评估心肌梗死后存活心肌。方法18例准备进行血运重建术心肌梗死患者,于术前1-5天行RT-MCE检查,并于术后3个月再次行常规超声心动图检查,室壁运动分析采用18节段分析法,分为运动正常、运动减弱、无运动和反常运动。心肌存活定义为术后超声检查室壁运动明显改善。将造影结果分为3种情况：充盈缺损,造影剂充盈延迟、回声稀疏不均匀或心内膜下充盈缺损,回声均匀性增强。其中后两种情况定义为存活心肌。结果在18例心肌梗死患者中共检出109个室壁运动异常节段,运动减弱为47个,无运动为56个,反常运动为6个。注射造影剂后回声均匀性增强的心肌节段中有2个节段术前室壁运动减弱,术后运动均改善;回声不均匀或心内膜下充盈缺损的心肌节段中术前室壁运动减弱有24个节段,术后运动改善14个,术前室壁无运动有24个节段,术后运动改善20个;充盈缺损的心肌节段中术前室壁运动减弱有21个节段,术后运动均未改善,术前室壁无运动32个,术后运动改善2个。RT-MCE检出存活心肌的敏感性、特异性分别为94.7%、78.9%。结论RT-MCE能比较准确的判断心肌梗死后心肌的存活性。

Objective We attempted to evaluate the myocardial viability after myocardial infarction with intravenous myocardial contrast echocardiography. Methods Intravenous real-time myocardial contrast echocardiography was performed in 18 patients with myocardial infarction before coronary revascularization. Follow-up echocardiography was performed 3 months after coronary revascularization. Segmental wall motion was assessed using 18-segment LV model and classified as normal, hypokinesis, akinesis and dyskinesis. Viable myocardlum was defined by evident improvement of segmental wall motion 3 montbs after coronary revascularization. Myocardial perfusion was assessed by visual interpretation and derided into 3 conditions： homogeneous opacification; partial or reduced opaciflcation or subendocardial contrast defect. The former two conditions were used as the standard to define the viable myocardium. Results Totally 109 abnormal wall motion segments were detected among 18 patients with myocardial infarction. Forty-seven segments were hypokinesis, 56 segments were akinesis and 6 segments were dyskinesis. The wall motion of 2 segments with hypokinesis before coronary revascular ization which showed homogeneous opacification, 14 of 24 segments with hypokinese and 20 of 24 segments with akinese before coronary revascularization which showed partial or reduced opaciflcation or subendocardial contrast defect improved 3 months after coronary revascularization. In our study, the sensitivity and specificity of evaluation of myocardial viability after myocardial infarction by intravenous real-time myocardial contrast echocardiography are 94.7 %, 78.9 %, respectively. Conclusion Intravenous real-time myocardial contrast echocardiography can accurately evaluate myocardial viability after myo cardial infarction.