POSTSTENOTIC AND POSTSTENOTIC FLOW MEASUREMENT TO ASSESS SEVERITY OF CORONARY-ARTERY STENOSIS

The purpose of this study was to investigate differences between prest enotic and post; stenotic intracoronary Doppler flow velocities and to determine whether these hemodynamic parameters of coronary flow demon strate a correlation with geometrically measured coronary artery steno sis. A low-profile (0.018-in.) Doppler angioplasty guidewire capable o f providing spectral flow velocity data was used to measure blood flow velocities both proximal and distal of 95 coronary artery stenoses ra nging from 15% to 82% in diameter:Percent diameter stenoses were analy zed by quantitative coronary arteriography. In comparison with presten otic measurements poststenotic Doppler flow velocities were markedly r educed in coronary artery stenoses with a diameter reduction greater t han 50% in quantitative angiography. In stenoses less than 50% nb diff erence between prestenotic and poststenotic parameters of coronary flo w could be found. Prestenotic Doppler data demonstrated no correlation to percent diameter stenosis, whereas poststenotic flow data correlat ed moderately with percent diameter stenosis. Poststenotic Doppler dat a of stenoses below 50% differed significantly from stenoses above 50% . In conclusion, intracoronary Doppler flow velocity measurements perf ormed distal to coronary artery stenoses contribute to the evaluation of hemodynamic significances of particular coronary artery stenoses.