Pulsed Doppler evaluation of diameter, blood velocity and blood flow of common carotid artery in sustained essential hypertension.

Diameter, blood flow velocity, and volumic flow of the common carotid artery were measured in 38 patients with sustained essential hypertension and compared with those of 38 age-matched normal subjects. Both hypertensive and control subjects were classified according to age into those younger and those older than 45 years. For the determinations, a pulsed Doppler velocimeter with an adjustable range-gated time system and a double transducer probe was used. In the younger group, the diameter of the common carotid artery had a similar value in hypertensive patients (0.639 +/- 0.014 cm) and in controls (0.651 +/- 0.015). The same level of blood flow velocity in hypertensive patients (19.7 +/- 0.9 cm/s) and in controls (21.2 +/- 0.9 cm/s) was observed. Therefore, the volumic flow was equal in the common carotid artery of the hypertensive patients (385 +/- 20 ml/min) and of the normotensive subjects (410 +/- 23 ml/min). In the older group, blood flow velocity was reduced in the common carotid artery of the hypertensive patients (19.4 +/- 1.0 cm/s vs. 15.6 +/- 0.6 cm/s; p less than 0.01), but the diameter was unchanged (0.653 +/- 0.018 cm in hypertensive patients and 0.665 +/- 0.018 cm in controls). Thus, there was a significant reduction of volumic blood flow in common carotid artery of the hypertensive patients over 45 years (321 +/- 14 ml/min). A negative relationship was observed between common carotid artery blood flow and age in elderly hypertensive patients (r = -0.42; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)