How can hepatic venous pressure gradients in patients with cirrhosis be used to differentiate between cardiac cirrhosis and portopulmonary hypertension?  

Chronically elevated right-sided filling pressures can lead to a phenotypic appearance of cirrhosis (ascites, cirrhotic appearance) without severe intrinsic hepatic dysfunction. The increased pressures are directly transmitted to the liver, with the right atrial pressure being functionally the same ...

This can be a bit tricky. If a person has portopulmonary htn, their hepatic wedge pressure minus the free hepatic pressure will be > 6 with differences > 10 showing signs of significant portal hypertension. Cardiac cirrhosis shows that pressures are consistently elevated from the right atrium ...

HVPG is a measure that quantifies the increase in sinusoidal resistance to blood flow and can be obtained in a minimally invasive way compared to portal venous sampling directly which may be more invasive. HVPG is the pressure difference between hepatic vein wedge pressure (HVWP) & hepatic vein ...