实时心肌声学造影与二维应变成像技术评价心肌梗死后患者心肌存活性

目的 探讨实时心肌声学造影与二维应变成像技术评价心肌梗死后患者存活心肌的价值.方法 20例准备进行血运重建术心肌梗死患者,于术前1周内行实时心肌造影检查,根据心肌灌注结果进行半定量评价:3分为充盈缺损,2分为回声稀疏不均匀及心内膜下充盈缺损,1分为回声均匀性增强;MCE定义心肌存活性为心肌灌注计分≤2分,而心肌充盈缺损表示无心肌存活性.血运重建术前及术后3个月分别获取心尖位四腔、两腔及左心长轴切面二维图象,进行室壁运动评分,根据术后的室壁运动有否改善分为存活心肌组和无存活心肌组,测定术前左室各节段心肌的收缩期纵向峰值应变.结果 (1) 血运重建术前,二维超声心动图发现共有90个室壁明显发生节段性运动异常,其中有70个室壁的节段性运动异常术后得到改善.(2)血运重建术前,实时心肌声学造影评价存活心肌为65节段,无存活心肌为25节段,敏感性、特异性及准确性分别为93.8%、64%和85.5%.(3) 存活心肌组术前心肌收缩期纵向峰值应变明显高于无存活心肌组(-7.34±5.84)% vs (-2.11±1.66)%,P＜0.001].以术前心肌收缩期纵向峰值应变≤-5.0%作为截断值判断心肌梗死时存活心肌的敏感性为72%,特异性为85%.结论 实时心肌声学造影可以准确地预测梗死心肌的存活性;同时二维应变成像技术以术前心肌收缩期纵向峰值应变≤-5.0%作为截断值也可以预测梗死心肌的存活性,其敏感性和特异性与实时心肌声学造影相当.

Myocardial Viability in Patients with Post-myocardial Infarction Using Real-time Myocardial Contrast Echocardiography and Two-dimensional Strain Echocardiography

Objective We attempted to evaluate myocardial viability in patients with post-myocardial infarction with real-time myocardial contrast echocardiography(RT-MCE)and Two-dimensional strain echocardiography.Methods Intravenous RT-MCE were performed in 20 patients with post-myocardial infarction before revascularization.Myocardial perfusion was assessed by visual interpretation.The results were divided into 3 conditions：contrast defect＝3；partial or reduced opacification or subendocardial contrast defect＝2；homogeneous opacification＝1,presence of viability was defined as the presence of contrast effect(score≤2).Two-dimensional images were recorded from the left ventricular four-chamber view,two-chamber view and the apical view before and after revascularization.According to ventricular wall motion improved after revascularization the patients were divided into viable myocardium group and non-viable myocardium group.The peak systolic longitudinal strain was measured in the apical views before operation.Results (1) 90 significantly abnormal segmental wall motions were found by two-dimensional echocardiography before revascularization,70 out of which were improved postoperation.(2) Viable myocardium group had 65 segments and non-viable myocardium group had 25 segments detected by RT-MCE before revascularization.The sensitivity,specificity and accuracy were 93.8%,64% and 85.5% respectively.(3) The peak systolic longitudinal strain of viable myocardium group were significantly higher than that of the non-viable myocardium group［(-7.34±5.84)% vs (-2.11±1.66)%,P＜0.001］.On taking peak systolic longitudinal strain ≤-5.0% as a cut-off value for detecting survived myocardium,the sensitivity and specificity were 72％ and 85％ respectively.Conclusions RT-MCE can accurately assess myocardial viability.Taking peak systolic longitudinal strain ≤-5.0% as a cut-off value can also assess myocardial viability.Its sensitivity and specificity is in line with the former.