Normal histology	Histopathology	Pathological basis of disease	Clinical findings	
Vascular architecture:
•	Terminal branches of the hepatic artery & hepatic portal vein are located at the angle of the lobule boundaries in portal tracts.
•	Blood from the portal tracts converges upon the central vein via sinusoids which pass between plates of hepatocytes.
•	The hepatic vein drained to the superior vena cava to the right atrium. 	•	Distention of central veins & sinusoids.
•	Central hepatocyte degeneration.
•	Central regions of the hepatic lobules are grossly red-brown.
•	Nutmeg pattern results from congestion around central vein.
•	There is centrilobular necrosis with hepatocyte drop-out & hemorrhage as central portion of the hepatic lobule is the last to receive blood.
•	Hepatic fibrosis in long-standing, severe congestion.	Causes:
•	Right heart failure
•	Hepatic vein or superior vena cava obstruction.

Pathogenesis:
•	In right heart failure, pumping force of right atrium & ventricle is compromised.
•	Blood is dammed at right atrium & may reflux back into liver.
•	Hepatic veins, central veins & capillaries are congested.	•