Influence of Sodium Intake on Left Ventricular-arterial Coupling

Inclusion Criteria: * Hypertension stage 1, with medium or high risk, when the treatment (mono or therapy without diuretics) is efficient, when the great pressure is reached (\<140/90 mmHg) * High sodium intake (sodium urinary excretion for 24h (UNaV) \> or = 170 mmol/24h before visit 0 * Limited sodium intake objective (UNaV\<85 mmol/24h)attempted at the end of the limited sodium intake period of 2 weeks * Patients aged between 18 and 80 years * Subject has given written informed consent * Subject has subscribed a health care insurance Exclusion Criteria: * Secondary hypertension * Complications associated with the arterial hypertension : history of cardiovascular diseases or myocardial infarction, cerebrovascular accident, coronary disease, ... * Arterial hypertension associated with cardiopathy * Arterial hypertension associated with nephropathy * Arterial hypertension associated with diabetes * Measure of central arterial pressure by tonometry is impossible * Cardiac echogenicity is not satisfactory for the analysis of left ventricular loop analysis * Patient refuses informed consent * Follow-up impossible for 15 weeks * Pregnant or women without efficacy contraception * Patient without freedom by administration decision * Patient in exclusion period * Patient without french insurance * Adult protected by the law