Increased regional sympathetic nervous activity in human hypertension: causes and consequences.

Biochemical, electrophysiological, pharmacological and haemodynamic findings provide evidence for the existence of sympathetic nervous system activation in some patients with primary human hypertension, particularly younger ones. Sympathetic activation has been shown to involve neural outflows to the heart, kidneys and skeletal muscle. This sympathetic nervous stimulation, the cause of which remains obscure, appears to be commonly important in the pathogenesis of the hypertension. Whether the sympathetic overactivity has adverse effects in addition to its effect on blood pressure, by promoting left ventricular hypertrophy, cardiac arrhythmias and atherogenesis, is at present uncertain.