Aims Patients with cirrhosis and portal hypertension are at high risk of developing complications such as variceal hemorrhage, ascites, and cardiac dysfunction, the latter of which is known as cirrhotic cardiomyopathy. Since non-selective beta-blockers (NSBB) may aggravate hemodynamic complications we investigated the effect of real-time propranolol infusion on cardiac function in patients with varying degrees of cirrhosis. Methods Thirty-eight patients with Child-Pugh A (n = 17), B (n = 17) and C (n = 4) underwent liver vein catheterization and cardiac magnetic resonance imaging. We assessed the effect of real-time propranolol infusion on the hepatic venous pressure gradient, cardiac index, stroke volume, ejection fraction, heart rate, and contractility. Results Nineteen patients were classified as responders to beta-blocker therapy. In pooling Child-Pugh B and C patients, the reduction in cardiac index by beta-blockade was weaker than in Child-Pugh A patients (-8.5% vs. -20.5%, p = 0.043). The effect of NSBB on portal pressure was inversely correlated to changes in the left atrium where the left atrial volume changed by 4 mL ±18 in responders compared to 15 mL±11 in non-responders (p = 0.03). Finally, the baseline ejection fraction correlated inversely with the reduction in portal pressure (r = -0.39, p = 0.02). Conclusion We found the effect of beta-blockade on cardiac index in patients with advanced cirrhosis to be less potent than in patients with early cirrhosis, indicating that underlying cirrhotic cardiomyopathy increases, and the cardiac compensatory reserve becomes more compromised, with disease progression. The differential effects of beta-blockade in the left atrium may be used to predict the effect of beta-blockers on portal pressure, but further studies are needed to investigate this possibility.