[Early changes in the circulation of the humeral artery in borderline arterial hypertension].

The brachial artery diameter and blood flow rate were measured by pulsed Doppler velocimetry in 9 healthy subjects and 24 patients of the same age group with borderline hypertension. To evaluate the results, the patients were divided into two groups according to their cardiac output: high cardiac output group (i.e. patients whose cardiac output was superior to the mean +/- 2 S.D. value in the control population), and normal cardiac output group (i.e. cardiac output lower than that value). Patients in both groups were of the same age and had the same level of blood pressure. The brachial artery diameter and blood flow rate values were the same in the normal cardiac output group and in the control population. However, these values were significantly higher in patients with high cardiac output than in controls (P less than 0.05 and P less than 0.001) and in patients with normal cardiac output (P less than 0.01). These results suggest that the haemodynamic profile in the brachial artery is not the same in all patients with borderline hypertension: there was a tendency to vasoconstriction in patients with normal cardiac output, whereas the brachial artery was clearly dilated in patients with high cardiac output.