DOPPLER GUIDE-WIRE FLOW-VELOCITY INDEXES MEASURED DISTAL TO CORONARY STENOSES ASSOCIATED WITH REVERSIBLE THALLIUM PERFUSION DEFECTS

A Doppler guide wire was used to measure phasic coronary blood flow ve locity distal to coronary stenoses in 17 symptomatic patients with cor responding positive exercise or adenosine thallium scintigrams. Distal average peak velocity and diastolic/systolic flow-velocity ratio were obtained in 16 vessels with stenoses (55% to 85% diameter stenosis) a nd a corresponding reversible thallium defect and in 11 control vessel s with no stenosis or thallium defect. Coronary flow-velocity reserve was obtained with intracoronary adenosine. Coronary flow reserve (2.3 +/- 0.4 vs 1.2 +/- 0.3, p < 0.01) and diastolic/systolic flow-velocity ratio (1.95 +/- 0.56 vs 1.44 +/- 0.59, p < 0.04) were significantly d ifferent between normal vessels and distal to stenoses, respectively. Excellent concordance between distal coronary flow reserve and diastol ic/systolic flow-velocity ratio to thallium scintigraphy was noted. A coronary flow reserve of <1.8 and a diastolic/systolic flow-velocity r atio of <1.7 predicted a reversible thallium perfusion scintigram (con cordance 96% and 88%, respectively). Distal coronary flow velocity ind exes may provide an alternative means of physiologic assessment of les ion severity during coronary angiography.