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 as the hepatic vein. Over time, this chronic pressure can change cellular structure and lead to portal hypertension which is reflected by a hepatic wedge pressure that is significantly higher than the hepatic vein, this is known as the trans hepatic gradient or hepatic vein pressure gradient (usually they are within 2-4mmHg). This is important as an appearance of cirrhotic morphology without intrinsic portal hypertension is a much lower risk for ...

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 free pressure (HVFP). HVWP reflects pressure in the portal venous system and HVFP reflects systemic venous pressure. HVPG ≤ 5 is usually considered to be normal and > 5 is indicative of portal hypertension. A normal HVPG is noted in patients with noncirrhotic causes of portal hypertension despite severe portal hypertension. HVPG is typically used for risk stratification of portal hypertension. RV failure (cardiac cirrhosis) could result in post-hepat...

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 into the intrahepatic system without a pressure gradient noted.