Effect of Beta-adrenergic Blockade on Elevated Arterial Compliance and Low Systemic Vascular Resistance in Cirrhosis

Abstract

BACKGROUND: Patients with cirrhosis exhibit a characteristic hyperdynamic circulation with increased cardiac output and heart rate and reduced systemic vascular resistance. The compliance of the arterial tree has recently been reported to be increased in these patients, who are often treated with beta-blockers, but the effect of this treatment on arterial compliance has not been investigated. The aim of the present study was therefore to assess the effects of propranolol on the arterial compliance of patients with cirrhosis. METHODS: Twenty patients with cirrhosis underwent a haemodynamic investigation with determination of splanchnic and systemic haemodynamics. Arterial compliance was determined as the ratio of the stroke volume to the pulse pressure and compared to normal values. RESULTS: All the patients had significant portal hypertension, with a mean hepatic venous pressure gradient (HVPG) of 17.8 mmHg, and responded to beta-blocker treatment with a significant reduction in the HVPG (-16%; P < 0.001). Arterial compliance was elevated (1.27 versus controls 1.01 ml/mmHg; P < 0.001), but remained almost unchanged during beta-adrenergic blockade (1.27 versus 1.29 ml/mmHg, +2%, ns), whereas systemic vascular resistance increased substantially (1083 versus 1378 dyn x s x cm-5, +27%; P < 0.001). The mean arterial blood pressure (-6%; P < 0.05), heart rate (-20%; P < 0.001), cardiac output (-25%; P < 0.001) and hepatic blood flow (-22%; P < 0.001) fell significantly. CONCLUSIONS: Treatment with beta-blockers increases small vessel (arteriolar) vascular tone towards the normal level, but does not affect the elevated compliance of the larger arteries in patients with cirrhosis.