Skeletal muscle blood flow and neurovascular reactivity in liver disease.

There was no significant difference in forearm muscle blood flow, measured by the clearance of (133)Xenon when 38 patients with liver disease were compared with 38 normal subjects. Patients with a clinically hyperdynamic circulation, finger clubbing, and previous portocaval anastomoses were included in the study. The changes in forearm skeletal muscle blood flow and pulse rate caused by a head-up tilt of 70 degrees were measured in 15 patients with chronic liver disease and 15 age-matched controls. Head-up tilting resulted in significantly less peripheral vasoconstriction and tachycardia in the group with liver disease than in the control group. These results suggest an impairment of baroreceptor-mediated sympathetic reactivity in liver disease. Such a defect might explain the relative rarity of hypertension in patients with cirrhosis.