The use of velocity wave form analysis in the diagnosis of carotid artery occlusive disease.

Velocity wave form analysis (VWFA) was carried out on 75 velocity tracings recorded from the common carotid artery with a continuous wave Doppler. Grouped according to clinical status, there were 20 young "normals" (I), 18 old "normals" (II), 15 stenoses of less than 50% diameter (III), 13 stenoses of greater than 50% (IV), and nine complete occlusions (V). Five of the nine dimesnions analyzed were found to be more discriminating than the others. Using these dimensions in an equation derived by discriminant analysis, the "score" of each tracing placed it into the appropriate clinical category with 95% accuracy. The accuracy rate of separating normal, stenosed, and occluded carotids was 100%. The accuracy of VWFA was limited (82%) only in discriminating between greater than and less less than 50% stenosis by diameter. Twenty-one of the 37 patients identified by VWFA as having carotid artery occlusive disease (CAOD) had normal supraorbital artery Doppler tests. Highly significant improvements in the velocity wave form of 10 carotid arteries were produced by endarterectomy.