[The baroreflex pathway and essential arterial hypertension]

The function of every baroreflex nervous pathway, and the influence of a diuretic treatment, were investigated in a group of 26 patients with essential hypertension and 24 normals measuring their blood pressures and R-R intervals while at rest and during the Valsalva manoeuvre, deep breathing at 6 breaths/min, standing up from a lying position, handgrip, and psychic stress. Eight hypertensive subjects were studied before and after the diuretic suppression. The precocious R-R and systolic responses to the standing up were smaller in hypertensive patients that in normals, and this decreased when the degree of hypertension augmented. Both anomalies persisted in patients with diuretics treatment and normal blood pressures. All this suggest smaller velocity or later initiation of the cardiac orthosympathetic response.