Left main coronary flow velocity associated with stenosis. Evaluation by transesophageal color-guided pulsed Doppler...

To quantitatively estimate the extent of left main coronary artery (LMCA) stenosis, flow velocity of the LMCA in 33 patients was analyzed by a transesophageal color-guided pulsed Doppler technique. In 11 of 20 patients with LMCA stenosis, coronary flow velocity could be measured. The peak diastolic flow velocity at the stenotic segments was 90 +/- 32 (SD) cm/s which was significantly greater than that at the nonstenotic segments (n = 13; 34 +/- 8 cm/s; p < 0.01), and was correlated with the angiographically determined percentage of diameter stenosis of the vessel which ranged from 52 to 90 percent (r = 0.77; y = 6.34 square root of x + 10.4; p < 0.01). These results suggest that acceleration of flow velocity at the point of stenosis may be correlated with the severity of the stenosis. Measurement of flow at the point of stenosis by transesophageal color-guided pulsed Doppler technique may facilitate the quantitative assessment of LMCA stenosis, although its sensitivity requires improvement.