[Effects of rilmenidine on arterial parameters in essential arterial hypertension].

Rilmenidine (RIL) is a new antihypertensive agent which lowers sympathetic tone, so reducing systemic peripheral resistance. The effects of a single dose of RIL (1 mg) on arterial function were the object of a preliminary randomised double-blind versus placebo trial in 14 patients with hypertension after a one month washout period on placebo. The following parameters were recorded before (T0) and 4 hours after administration (T4): blood pressure, heart rate (automatic recordings), diameter of the humeral artery (D), mean blood flow velocity (Vm) by an 8 MHz duplex pulsed Doppler system, local forearm resistances (LR = mean BP/D2 Vm/4), carotid-femoral pulse wave velocity (PWV) and humeral arterial wall tension (mean BP.D/2). The two groups were compared by statistical analysis of variance with two crossed factors. RIL significantly lowered systolic BP (p less than 0.02), diastolic BP (p less than 0.05) and mean BP (p less than 0.01) without changing the heart rate. The D and PWV were unchanged in the RIL group. There was a significant improvement in arterial wall tension (-6.7% vs + 1.1%; p = 0.02) associated with a tendency to increase the PWV (45% vs 4%; p = 0.097) and to decrease LR (46% vs 10%; p = 0.062) although those changes were not statistically significant compared with those observed with placebo. These initial results indicate that the hypotensive effect of RIL is accompanied by a reduction in humeral arterial wall tension which occurs without any change in arterial diameter. This also reflects a change in the pressure-volume relationship with RIL.(ABSTRACT TRUNCATED AT 250 WORDS)