Selection of Hypertensive Patients for Sympathectomy

The demonstration that surgical sympathectomy may favorably influence the course of essential hypertension in man has given emphasis to the role of the autonomic nervous system in the pathogenesis of this disease. Indeed there is much to indicate that (1) neurogenic vasoconstriction is of prime importance in human hypertension and that (2) renal ischemia is a secondary rather than a fundamental phenomenon in its mediation. Obviously, sympathectomy can be successful only in those instances in which vasospasm is due wholly or in large part to neurogenic influences. As there has been no method by which automomic activity could be accurately quantified in man, selection of patients for surgery has proved difficult. A test that could determine the presence and degree of participation of a neurogenic element would be valuable. The sodium amytal, sodium nitrite and cold pressor tests, although still widely used, have given ample demonstration of their inability to