The aim of the research is to evaluate the Subendocardial Viability Ratio (SEVR) in hypertensive patients, using non-invasive arterial tonometry, and to establish the influencing factors and the possibility of predicting cardiovascular morbidity and mortality in arterial hypertension. The SEVR will be evaluated on all patients belonging to the Arterial Hypertension Centers undergoing non-invasive arterial tonometry. The SEVR is calculated on the morphology of the central pressure wave as the ratio between the DPTI (diastolic pressure-time index), i.e. the area between the carotid pressure curve and the ventricular pressure curve during the diastolic phase, and the SPTI ( systolic pressure-time index), i.e. the area under the carotid pressure curve during the systolic phase. The SEVR will be correlated with the anthropometric and pathology variables which will be collected in an appropriate database.