Adrenergic Blockade in Hypertension

Excerpt

HYPERTENSION with its sequelae is the second most common cause of death after atherosclerosis in the United States. A great deal of work has been done in the past decade to define the pathogenesis and to rationalize therapy for so-called essential hypertension. There is a suggestion that hyperactivity of the central and peripheral sympathetic nervous system either in response to stress or de novo leads to hypertension in some patients. A decline in blood pressure (BP) in hospitalized patients and during relaxation states (eg, meditation) lends support to this theory.

Experimental application of epinephrine to hypothalamic or medullary receptors has resulted in sympathetic discharge and an increase in systemic BP. Some persons have been shown to have hyperdynamic circulation characterized by high plasma catecholamine levels, tachycardia, systemic hypertension, and high cardiac output in the early phase of hypertension. Long-standing hypertension increases the sodium content of the arteriolar wall and eventually