[Mechanisms of essential arterial hypertension].

Despite a very simple haemodynamic equation of blood pressure (cardiac output multiplied by systemic vascular resistances), the precise mechanisms of essential hypertension are still unknown. Blood pressure level is determined by many physiologic systems which are submitted to complex interactions; the 2 main anomalies associated with hypertension are a primitive defect in renal excretion of sodium and an excessive rise of vascular tone. Hypertension is probably a polygenic disease, with several abnomalies in these systems interacting with a particular environment. Genetic data have recently reinforced this concept by demonstrating a link between hypertension and particular alleles of candidate genes in some population groups.