[Sympathetic nervous factors, pressure variability and organ damage in arterial hypertension]

Animal models have shown that hypertension may be accompanied by an increase in sympathetic activity. The findings of increased plasma norepinephrine or increased muscle sympathetic nerve traffic have now provided clear evidence, however, that sympathetic activity is increased in essential hypertension and that adrenergic neural mechanisms are already involved in the early phase of this condition. Furthermore, in the early and late phases of hypertension, the presence of other cardiovascular risk factors frequently accompanying hypertension such as obesity, insulin-resistance, and smoking, concomitant with hypertension, brings about sympathetic activation which may be superimposed on the activation resulting from the hypertensive state itself. Finally, sympathetic activation is directly involved in the progression of end-organ damage and plays a paramount role in the cardiovascular structural changes typical of the blood pressure elevation occurring in left ventricular hypertrophy, arteriolar remodeling, and atherosclerosis. These findings underscore the importance of aiming anti-hypertensive treatment at the reduction not only of blood pressure levels, but also of enhanced sympathetic cardiovascular drive.