Lin Yunjia, Guan Xin, Ren Kai, Zhu Yanbo, Lu Yaping, Shang Yanwen
Department of Ultrasound, Tianjin Chest Hospital, Tianjin 300222, P.R. China.
Cardiac Intensive Care Unit, Tianjin Chest Hospital, Tianjin 300222, P.R. China.
Exp Ther Med. 2020 Aug;20(2):1315-1320. doi: 10.3892/etm.2020.8813. Epub 2020 May 28.
The study aimed to investigate the role of low-dose dobutamine stress myocardial contrast echocardiography (MCE) in evaluating myocardial local microcirculation and predicting cardiac function recovery in patients with myocardial infarction. A total of 50 patients with acute myocardial infarction (AMI) were enrolled in the present study. Positron emission tomography was used as a gold standard to determine viable/non-viable myocardial segments in infarcted myocardial region. MCE and dobutamine stress MCE were carried out 72 h after PCI. MCE was carried out again to evaluate myocardial condition at 6 months after PCI. As compared with normal myocardial segments, resting MCE revealed a significant decrease of the values of A (the peak intensity of the time-perfusion intensity curve, reflecting the myocardial blood volume), β (the slope of the curve, reflecting the myocardial blood flow (MBF) velocity) and A x β (reflecting MBF) of viable and non-viable myocardial segments. After being challenged by dobutamine, the values of A, β and A x β of normal coronary blood supply areas were significantly increased; while the segments A and A x β of viable myocardium were markedly decreased. Patients were further divided into two groups based on the changes in the contrast-enhanced index (CSI) following dobutamine loading. In the dobutamine stress echocardiography-positive group (the CSI increased or decreased by >0.2), the left ventricular ejection fraction was significantly increased and pro-B-type natriuretic peptide significantly decreased at 6 months following intervention. Low-dose dobutamine stress MCE was indicated to be an effective method to evaluate myocardial microcirculation perfusion in patients with AMI following PCI. In addition, CSI, as a simple semi-quantitative index, may predict left ventricular function in patients with AMI.
本研究旨在探讨小剂量多巴酚丁胺负荷心肌对比超声心动图（MCE）在评估心肌梗死患者心肌局部微循环及预测心功能恢复中的作用。本研究共纳入50例急性心肌梗死（AMI）患者。采用正电子发射断层扫描作为金标准来确定梗死心肌区域存活/非存活心肌节段。PCI术后72小时进行MCE和多巴酚丁胺负荷MCE。PCI术后6个月再次进行MCE以评估心肌状况。与正常心肌节段相比，静息MCE显示存活和非存活心肌节段的A值（时间-灌注强度曲线的峰值强度，反映心肌血容量）、β值（曲线斜率，反映心肌血流（MBF）速度）和A×β值（反映MBF）显著降低。多巴酚丁胺激发后，正常冠状动脉供血区的A、β和A×β值显著升高；而存活心肌节段的A和A×β值明显降低。根据多巴酚丁胺负荷后对比增强指数（CSI）的变化将患者进一步分为两组。在多巴酚丁胺负荷超声心动图阳性组（CSI升高或降低>0.2），干预后6个月左心室射血分数显著升高，B型利钠肽原显著降低。小剂量多巴酚丁胺负荷MCE被证明是评估PCI术后AMI患者心肌微循环灌注的有效方法。此外，CSI作为一个简单的半定量指标，可能预测AMI患者的左心室功能。
