The review emphasizes on the sympathetic and parasympathetic abnormalities in essential hypertension, the possible mechanisms underlying these abnormalities, and their importance in the development and progression of the structural and functional cardiovascular (CV) damage that characterizes hypertension.
Apart from being a hemodynamic phenomenon, primary hypertension is a vicious syndrome involving abnormal adiposity, overactivation of the adrenergic system, metabolic abnormalities, and activation of the immune system. Physiological studies have established the key role played by the autonomic nervous system in modulating CV functions and in controlling arterial pressure values. Many factors contribute to increased sympathetic nerve activity in metabolic abnormalities including obesity, impaired baroreflex sensitivity, hyperinsulinemia, and elevated adipokine levels.
Experimental and clinical investigations clearly indicate that the origin, progression, and outcome of hypertension are related to dysfunction of the autonomic CV system, especially to abnormal activation of the adrenergic division. The activation of the sympathetic nervous system is essential in energy homeostasis and can exert intense metabolic effects. Accumulating data from a number of studies suggest that central sympathetic overactivity plays a crucial role in the causative factors and complications of several metabolic conditions that can cluster to form the metabolic syndrome.
This review provides an evidence of attenuation of autonomic CV control in essential hypertension and that sympathetic overdrive is a major component of this autonomic dysregulation. Arterial pressure control requires complex integration of regulatory mechanisms across multiple physiological systems. A continuous increase in blood pressure therefore, reflects a failure of one or more of these controls.
The findings discussed herein provide a rationale for pursuing sympathetic deactivation by nonpharmacological as well as pharmacological interventions aimed at lowering elevated blood pressure values and protecting patients from hypertension-related complications.
How to cite this article
Verma N. Sympathetic Nervous System and Hypertension. Hypertens J 2017;3(1):27-36.