[Essential arterial hypertension. From notion to treatment]

Arterial hypertension (AH) is an excessive elevation of the arterial blood pressure (ABP) in the systemic circulation. It is, however, arbitrary to define a limit between normal and pathological ABP, since the ABP varies in a continuous fashion with the population. Occasional measurement of the blood pressure by sphygmomanometer is rather inaccurate but still remains the method of reference. A more precise determination of the ABP is possible by using the stress blood pressure profile and ambulatory measurement which are prognostically far superior to occasional measurement. AH is not a disease but a risk factor--quantitative and independent of the cardio-vascular system because it contributes to atherosclerosis and regional ischemic processes. The genesis of the so called essential AH still remains unclear, but it is getting better known: from a genetic factor of predisposition, the respective roles of the salt and the kidney as a filter are determining, along with the more or less appropriate action of hormonal factors of the sodium excretion. This is combined with the complex and synergistic action of potent vasopressor mechanisms such as the sympathetic nervous system and the renin-angiotensin systems--circulating as well as in the tissues. AH presents haemodynamic abnormalities, which vary according to age, and among which the elevation of systemic vascular resistances is most characteristic. This is combined with a lack of compliance of the large arterial vessels, and secondarily, a hypertrophy, partially adaptive, of the entire cardiovascular system. This includes left ventricular hypertrophy which has harmful effects on intracardiac and coronary haemodynamics, resulting in an increased mortality. It is therefore necessary that the treatment, not only decrease the blood pressure, but also take into account the regional vascular outputs while respecting and improving the renal, cerebral and coronary circulations with general improvement of the vascular compliance. The treatment must also result in an early and lasting decrease of the myocardial hypertrophy. This is why the new anti-hypertensive treatments (conversion enzyme inhibitors and calcium inhibitors) represent a desirable therapeutic alternative to the classical treatment. Their prescription follows a few general rules, but must, however, remain very personalized with evaluation of the results at two levels: individual control of the ABP and mass benefit in terms of decreased cardiovascular morbidity and mortality.