DETERMINATION OF CORONARY FLOW MEASUREMENTS BY TRANSESOPHAGEAL ECHOCARDIOGRAPHY - DEPENDENCE OF FLOW VELOCITY RESERVE ON THE LOCATION OF STENOSIS

Doppler velocimetry with the use of transesophageal echocardiography c an record flow in the proximal left anterior descending artery (LAD). To assess whether this limited sampling ability influences the recordi ng of velocity and the calculation of coronary flow reserve (CFR), 32 patients with LAD stenosis (4 ostial stenoses, 18 proximal stenoses, 1 0 mid-LAD stenoses) and 33 patients with arteriographically normal LAD s were studied. Basal flow and dipyridamole-induced hyperemic flow rat es were recorded. The mean basal flow Velocity in ostial stenoses was greater than in other groups, and the mean basal flow velocity in prox imal stenoses was less than that in mid-LAD stenoses and in the normal group. Maximal hyperemic Velocity did not differ between the groups. CFR in all stenoses groups was less than that in the normal group. Ost ial CFR was less than in ail other groups, and proximal CFR was less t han that in either the mid-LAD or the normal LAD groups. With this tec hnique, coronary flow velocimetry and estimation of CFR is affected by the location of stenosis.