The purpose of this study is to determine the effect on the (carbon 13 labelled(13C)-Methacetin Breath Test (MBT) of i.v. propranolol, a non-selective beta blocker (NSBB) following initial administration and after chronic use of each of these agents. The correlation of the MBT with Hepatic Venous Pressure Gradient (HVPG) measurement before and after treatment will be assessed. Additionally, the MBT measurements following 60 days of therapy will be compared to the first MBT measurement and to the second MBT measurement, post HVPG. Each patient's subsequent MBT measurement will be compared to his previous MBT results in order to determine his/her response to therapy.

Variceal bleeding is a life threatening complication of cirrhosis, which still carries a high mortality. Non selective beta-adrenergic blockers are effective at preventing first time variceal bleeding and re-bleeding. The efficacy of these drugs depends on the magnitude of reduction in portal pressure after administration, which varies widely between patients. Studies have shown that a reduction in portal pressure (as measured by HVPG) to 20% from baseline or to values ≤ 12 millimeters of mercury (mmHg) is associated with a low residual risk of bleeding . Patients with such a reduction are considered to be "responders" to beta blocker (BB) therapy. Unfortunately, a significant percentage of patients do not respond to therapy and need to be prescribed to an alternative therapy. The clinical application of this observation is limited since it requires a repeated HVPG measurement,which is not feasible in most cases. A non-invasive breath test that can assess portal pressure in correlation to HVPG and allow efficient management of patients at risk, could be very useful.

Inclusion Criteria:

-> 18 years old (M/F)

-Diagnosis of cirrhosis: i. By liver biopsy ii. Or strong suspicion of cirrhosis by accepted criteria for the clinical diagnosis of cirrhosis (e.g. peripheral edema or varices, palpable hard left lobe of the liver, small right lobe span or palpable splenomegaly), and/or radiological evidence of cirrhosis (by abdominal US, CT, or MRI, showing a nodular liver and/or portosystemic collaterals with portal vein patency and/or ascites and/or splenomegaly, and/or colloid shift on a colloid-isotope liver-spleen scan), and/or laboratory variables (platelets <100,000/mm3, albumin< 3.5g/dL, or international normalized ratio (INR)>1.3) iii. Presence of esophageal varices (without previous variceal bleeding episode) or HVPG≥10mmHg 12mmHg from previous testing.

-Has been scheduled for hemodynamic study testing, including response to acute therapy.-

Exclusion Criteria:

• Patients already receiving beta blockers
• Hepatocellular carcinoma
• Portal vein thrombosis
• Contraindications to non-selective beta blocker Propanolol
• Cholestatic liver disease
• Severe heart, pulmonary or renal disease.
• Patient has previous surgical bypass surgery for morbid obesity
• Patient has extensive small bowel resection
• Any major surgery in the past 3 months.
• Patient is a recipient of any organ transplant
• Patient allergic to acetaminophen.
• Patients who are taking hepatotoxic drugs
• Patient, based on the opinion of the investigator, should not be enrolled into this study.
• Patients unable or unwilling to sign informed consent
• Patients that are participating in other clinical trials evaluating experimental treatments or procedures or have participated in a clinical trial in the past 3 months.