This is thought to be due to direct centrizonal compression (18). It is less recognized that left-sided failure also leads to impairment of hepatic function due to a low-flow state (1-3,6,8). The mechanism is due to the fact that the liver gets a fixed amount of cardiac output (13); the decrease in flow is compensated for by an increase in oxygen extraction leading to anoxic necrosis in the centrizonal area. This is supported by a comparison of liver biopsies with and without centrizonal necrosis in patients with CHF; necrosis was only seen when also either marked venous congestion and/or hypoxemia existed (6). Of note is that even minor impairments of left ventricular function can lead to marked liver enzyme abnormalities (2,15); similarly, in known CHF, an episode of hypotension can be elicited in only 45 % (6). In chronic congestion, LFT's are abnormal dependent on the reduction in CO (10; figure 2).