Transthoracic Doppler echocardiography – noninvasive diagnostic window for coronary flow reserve assessment

Abstract

This review focuses on transthoracic Doppler echocardiography as noninvasive method used to assess coronary flow reserve (CFR) in a wide spectrum of clinical settings. Transthoracic Doppler echocardiography is rapidly gaining appreciation as popular tool to measure CFR both in stenosed and normal epicardial coronary arteries (predominantly in left anterior descending coronary artery). Post-stenotic CFR measurement is helpful in: functional assessment of moderate stenosis, detection of significant or critical stenosis, monitoring of restenosis after revascularization. In the absence of stenosis in the epicardial coronary artery, decreased CFR enable to detect impaired microvascular vasodilatation in: reperfused myocardial infarct, arterial hypertension with or without left ventricular hypertrophy, diabetes mellitus, hypercholesterolemia, syndrome X, hypertrophic cardiomyopathy. In these diseases, noninvasive transthoracic Doppler echocardiography allows for serial CFR evaluations to explore the effect of various pharmacological therapies.

Coronary Microvascular Dysfunction ― Epidemiology, Pathogenesis, Prognosis, Diagnosis, Risk Factors and Therapy ―

“…CFR is measured as the ratio of peak CBFV after vasodilator to CBFV at rest. 53 TTDE measurements have been found to be highly reproducible. 54 In addition, CFR measured by TTDE has been shown to have excellent correlation with CFR measured by PET 54 and intracoronary testing.…”

Diabetes mellitus and coronary microvascular function in asymptomatic patients with severe aortic stenosis and nonobstructed coronary arteries

“…1 It has been shown that CFR is impaired in asymptomatic patients with AS and normal coronary arteries, and that in these patients impaired CFR has a prognostic value. 2,3 The treatment of symptomatic patients with significant AS is well established, whereas the management of asymptomatic patients with severe AS and normal left ventricular ejection fraction (LVEF) is a matter of on-going debate.…”

Measurement of the coronary flow velocity reserve in patients with non-alcoholic fatty liver disease

“…The reduction in CFVR depends not only on severity of stenosis of the ECA, but also on a number of microvascular factors (19,20). Thus, decreased CFVR enables the detection of impaired microvascular vasodilatation in left ventricular hypertrophy, diabetes mellitus, hypercholesterolemia, smoking habit, and MS (19,20). In previous studies, TTDE has been used to show coronary microvascular insufficiency in coronary heart disease, type 2 diabetes mellitus and hemodialysis patients (17,21,22).…”

“…Transthoracic Doppler echocardiography (TTDE) is a cheap, noninvasive and repeatable method to evaluate the structural and functional status of the epicardial coronary arteries (ECA) (17,18). In the past few years, TTDE has attracted attention as a tool for accurate determination of reduced coronary flow velocity reserve (CFVR), the indicator for microvascular hypoperfusion.…”

“…CFVR is defined as a ratio between the maximal (stimulated) and the baseline (resting) coronary blood flow, and it is important for the understanding of the pathophysiology of coronary circulation. The reduction in CFVR depends not only on severity of stenosis of the ECA, but also on a number of microvascular factors (19,20). Thus, decreased CFVR enables the detection of impaired microvascular vasodilatation in left ventricular hypertrophy, diabetes mellitus, hypercholesterolemia, smoking habit, and MS (19,20).…”