More than half of the patients with symptoms suggestive of myocardial ischemia presenting at invasive angiography have no obstructive coronary artery disease (CAD). A large proportion of these patients have ischemia caused by coronary microvascular dysfunction, a condition associated with adverse cardiovascular prognosis. Measurement of coronary flow velocity reserve by transthoracic Doppler echocardiography is a feasible and reproducible method for the evaluation of coronary microvascular function. This review provides a practical overview of the method in a clinical setting of angina and noobstructive CAD, including technical details and prognostic significance.

中文翻译：

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经胸评估冠状动脉血流速度储备：心绞痛和无阻塞性冠状动脉疾病患者的诊断测试的一种实用方法

侵入性血管造影术中有一半以上的症状提示心肌缺血的患者没有阻塞性冠状动脉疾病（CAD）。这些患者中有很大一部分是由冠状动脉微血管功能障碍引起的局部缺血，这种疾病与不良的心血管预后有关。经胸多普勒超声心动图测量冠状动脉血流储备量是评估冠状动脉微血管功能的一种可行且可重复的方法。这篇综述提供了在心绞痛和无阻塞性CAD的临床环境中该方法的实用概述，包括技术细节和预后意义。