Sympathetic and baroreflex function in hypertension: implications for current and new drugs

The sympathetic nervous system has moved towards center stage in cardiovascular medicine. The importance of the sympathetic activation in heart failure and in renal insufficiency progression and mortality is indeed now well established. In essential hypertension evidence has been provided that this may be the case, because sympathetic overactivity is a key factor in the pathophysiology of the disease, thereby promoting not only the blood pressure increase but also the development and progression of the hypertension-related cardiovascular and metabolic complications, such as left ventricular hypertrophy, vascular hypertrophy, endothelial dysfunction, cardiac rhythm disturbances and insulin resistance. In this review article the main pathophysiologic and mechanistic features of the sympathetic overactivity characterizing the essential hypertensive state will be examined. This will be followed by an analysis of the effects of 1) the hyperadrenergic state on the cardiovascular risk profile as well as on the end organ damage and 2) the different antihypertensive compounds on sympathetic and baroreflex function. The rationale for obtaining during antihypertensive drug treatment an effective sympathoinhibition will be finally highlighted.