Direct Arterial Study of the Blood Pressure Response to Cold of Normotensive Subjects and Patients with Essential Hypertension before and during Treatment with Various Antihypertensive Drugs

Abstract
The cold pressor test was performed three times at 15-minute intervals on 65 normotensive subjects and on 60 patients with essential hypertension both before and during treatment with antihypertensive drugs. The arterial pressure was recorded directly from the radial artery. On the basis of differences in the cold pressor response among individuals in the control group, the criteria for normal reaction and for hyperreaction were modified. The cold pressor response in the patients with essential hypertension was markedly depressed by the ganglionic blocking agents, but was not affected by various combinations of hydralazine, protoveratrine and reserpine.