SKIN BLOOD-FLOW DURING VASOCONSTRICTIVE AND VASODILATIVE STIMULI IN ESSENTIAL-HYPERTENSION PATIENTS - A LASER-DOPPLER FLOWMETRY STUDY

In order to compare the extent of the elicited vasoconstrictive and va sodilative response at the microcirculatory level in essential hyperte nsion (EH), we measured the skin blood flow by means of a laser Dopple r flowmeter (LDF). Thirty-four mild-to-moderate EH patients were enrol led. Twenty-two sex- and age-matched healthy subjects were selected as a control group. The LDF measurements were carried out with the probe over the fingertip of the distal phalanx at baseline conditions (Rest flow, RF), after an ischaemic test (post-ischaemic peak flow) and dur ing an arithmetic stress test (AT), The flow was expressed in arbitrar y units. The data were processed using the Perisoft computer program. The relative flows after the ischaemic test (Rel Fl) and during the BT (Rel F2) were expressed as a percentage of the previous RF values (RF 1 and RF2, respectively), During the AT, the lag time was calculated ( in seconds), As compared to the control subjects, RF was significantly lower in the EW group (p < 0.01), During the AT, the EH patients show ed a statistically lower mean Rel F2 decrease compared to the control subjects (p < 0.01), No statistically significant difference occurred in the Rel Fl and lag time, These data suggest that the vasoconstricti ve capacity of the precapillary vessels is impaired in patients with h ypertension.