CORRELATES OF MIDDLE CEREBRAL-ARTERY BLOOD VELOCITY IN THE ELDERLY

We analyzed the association between hematologic factors and blood velocity of the middle cerebral artery in 42 healthy ambulatory subjects aged 63-86 years. We found a significant inverse association between mean velocity and both hematocrit (r= – 037, p<0.02) and fibrinogen concentration (r= —0.42, p <0.005). These two variables are independently associated with velocity and together explain 29% of the variance in mean velocity. Both hematocrit and fibrinogen concentration should be considered in the interpretation of transcranial Doppl er findings in this population. © 1990 American Heart Association, Inc.