Transthoracic echocardiographic visualization of coronary artery blood flow and assessment of coronary flow reserve in the right coronary artery: a first report of 3 patients.

Assessment of coronary flow reserve (CFR) has proven to be an important diagnostic tool providing useful clinical and physiologic information about coronary artery function. In several studies, the transthoracic echocardiographic assessment of CFR, defined as a ratio of hyperemic to basal coronary flow velocity, was validated in the left anterior descending artery. But so far, the visualization of coronary flow and the measurement of CFR were limited to the mid and distal portion of the left anterior descending artery. Introduction of a modified 2-chamber view enables the recording of coronary blood flow and the assessment of CFR in the posterior descending branch of the right coronary artery in selected patients. This report of 3 cases describes for the first time a method to visualize and measure coronary blood flow in the distal right coronary artery by precordial Doppler echocardiography.