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

A synthetic view of different anatomic (first row) and coronary flow reserve (CFR) response (last row). In the normal condition (left), there is a normal CFR response [ratio of hyperemic (light red, A′) to basal (dark red, A) peak diastolic coronary flow velocity >3]. An abnormal CFR response can be noted in the presence of microvascular disease or mild-to-moderate epicardial coronary artery stenosis (second column from left). With more advanced epicardial coronary artery stenosis (third column from left), more reduction of CFR is found.

Using a modified parasternal long-axis. (A) Transthoracic color Doppler recording shows coronary blood flow (arrows) in the distal portion of the (B) left anterior descending coronary artery. Ao=aorta; LA=left atrium; LV=left ventricle.

Transthoracic Doppler echocardiography showing (A) coronary blood flow; and (B) quantitative analysis.