Evaluation of coronary blood flow by transthoracic Doppler echocardiography

虽然确实是这样。经胸超声心动图难以显示心外膜冠状动脉血流，近年来超声仪器的发展使心外膜动脉血流显影成为可能。应用Sequoia系统经胸多普勒超声心动图检查冠状动脉血流，研究其对冠状动脉狭窄的诊断效果。高灵敏度的彩色和脉冲多普勒回波不仅可以有效地检测冠状动脉左前降支，而且可以检测左回旋支的近端。经胸超声心动图测量的左前降支的冠脉血流储备与有创法测量的左前降支血流储备相当(r=0.87，P<0.0001)。当DMVR为2.0或以上为异常高值时，诊断DS以上狭窄病变的敏感性和特异性分别为93%和93%，经胸彩色多普勒超声心动图可显示右冠状动脉间隔支至LAD的良好侧支血流，高灵敏度的经胸多普勒超声心动图对无创、准确评价冠状动脉狭窄有重要价值。

Although it was. difficult to visualize epicardia1 coronary artery blood by transthoracic echocardiography, recent development of ultrasound instrument enable to visualize epicardial artery flow. We investigated the detection rate oLthe coronary artery blood flow and studied the diagnostic efficacy of coronary artery stenosis by transthoracic Doppler echocardiography using Sequoia system.The highly sensitive color and pulsed Doppler echo allowed efficient detection not only of the left anterior descending coronary artery (LAD), but also the proximal portion of the left circumflex artery. It was found that the coronary blood flow reserve (CFR) of LAD measured by transthoracic Doppler echocardiography was comparable in accuracy with CFR measured by invasive methods (r=0.87, p<0.0001).Coronary flow mapping in LAD was performed by the color Doppler-guided pulsed Doppler and diastolic mean velocity ratio (DMVR) in LAD was calculated from highest diastolic mean velocity (HDMV) and lowest diastolic mean velocity (LDMV) (DMVR = HDMV/ LDMV). When DMVR was 2.0 or more which was regarded as an abnormally high value, stenotic lesion with 50% diameter stenosis (DS) or more DS was diagnosed with 93% sensitivity and 93 % specificity.The good collateral coronary blood flow through the septal branches from right coronary artery to LAD was visualized by transthoracic color Doppler echocardiography.Highly sensitive transthoracic Doppler echocardiography was very useful to evaluate non.invasively and accurately coronary stenosis.