Clinical Applications of Transthoracic Doppler Echocardiographic Coronary Flow Reserve Measurements in the Left Anterior Descending Coronary Artery

Transthoracic Doppler echocardiography (TDE) is a noninvasive tool for measuring coronary flow reserve in the epicardial coronary arteries. In the absence of stenosis in the epicardial coronary artery, TDE can detect impaired microvascular vasodilatation associated with diseases, including reperfused myocardial infarct, systemic arterial hypertension, diabetes mellitus, coronary vasospasm, microvascular angina, and hypertrophic cardiomyopathy by demonstrating a decrease in the coronary flow reserve. Because it is noninvasive, TDE allows for serial coronary flow reserve evaluations to explore the effect of various therapies. This noninvasive imaging technique expands the field of diagnostic echocardiography and brings new insight into the pathophysiology of ischemic heart disease. This review outlines rationale of TDE to evaluate coronary flow reserve in the left anterior descending coronary artery and discusses its clinical applications.