Abstract

To elucidate the mechanisms by which beta receptor blockade leads to a reduction of portal pressure, 18 patients with cirrhosis and portal hypertension were given comparable doses of propranolol or metoprolol. The fall in portal pressure was more marked with propranolol together with a significant reduction in hepatic blood flow, which was not seen with metoprolol. No correlation between the reduction in cardiac output and the decrease in portal pressure or changes in hepatic blood flow could be elicited in each group, but there was a direct relationship between the decrease in hepatic blood flow and fall in portal pressure in the propranolol treated patients. The difference observed may be related to blockade of beta 2 vasodilator receptors in the splanchnic circulation which will occur only with propranolol and lead to a greater fall in splanchnic blood flow than will be produced by a reduction in cardiac output alone. Metoprolol, by maintaining effective hepatic blood flow, may be preferable to propranolol in patients with severely impaired liver function.