NEW SEMIAUTOMATED DOPPLER METHOD FOR QUANTIFICATION OF VOLUMETRIC FLOW - INTRAOPERATIVE VALIDATION WITH MULTIPLANE TRANSESOPHAGEAL COLOR DOPPLER IMAGING

We have validated a new semiautomated method for quantification of vol umetric flow applied to multiplane transesophageal color Doppler mappi ng. This Doppler technique assumes only the incompressibility of the f luid and includes variations of flow area. By computing velocity vecto rs across a surface normal to the point of scanning, volumetric flow c an be measured independently of the angle of incidence between the ult rasonic beam and the direction of blood flow. Mitral valvular flow rat e was measured during surgery by transesophageal color Doppler echocar diography in 27 patients undergoing coronary artery bypass grafting at 45 sets of observations. The results were compared with those obtaine d by the thermodilution technique. The mean of the differences between the thermodilution technique and color Doppler echocardiography was 0 .06 +/- 0.866 L/min for the mitral valvular flows (mean of differences [thermodilution-color Doppler] +/- 2 SDs of differences). Thus mitral valvular volumetric flow measured by this color Doppler method showed a close agreement to the thermodilution technique during surgery.