Dynamics of the circulation in acute hypertension produced by stimulation of the cerebral cortex.

STIMULATION of areas of the cerebral cortex of dog, cat, monkey, and man is followed by a prompt rise in arterial blood pressure. No data are available to indicate whether this is due to increase in peripheral resistance or increase in cardiac output, nor is there any information as to whether comparable changes are produced in the lesser circulation. There are, however, a number of analogous situations which bear upon this. In man anxiety usually causes an increase in cardiac output, as measured by ballistocardiography, with decrease in peripheral resistance, but at times may cause elevation of blood pressure with increase in peripheral resistance. In the dog, acute hypertension produced by section of the buffer nerves is associated with maintenance of cardiac output and an increase in peripheral resistance. Acute hypertension produced by the intracisternal injection of fibrin is accompanied by a marked increase in peripheral resistance, together with an increase in pulmonary venous pressure and, at times, pulmonary edema.