Liver and heart failure: an ultrasound relationship

Liver and heart are anatomically and patho-physiologically related. In heart failure (HF) the increased right atrial pressure and volume overload cause histological changes in hepatocytes, leading to a condition known as "congestive hepatopathy" (CH), with consequent variations in liver functioning and ultrasound (US) findings. CH has specifical US findings especially regarding venous vessels aspect, easily detecting by gray-scale study, but many others can be distinguished by Doppler analysis. Usually, hepatic veins look enlarged and hypocollassing, together with signs of portal hypertension (hepatomegaly, ascites, splenomegaly, porto-systemic collaterals). Typically, in CH Doppler findings regard alterations in venous vessel flow and arterial resistance (venous system hyperpulsatility, reduced velocity flow, high resistance index in hepatic arterial Doppler spectrum). Sometimes CH and other primary hepatopathy can coexist, and therefore some of the expected variations may not manifest: it allows suspecting an unknown underlying liver disease. At last, US technologies of more recent applications, even if not routinely used, allow investigating additional aspects such as elastography that detects changes in liver elasticity or contrastographic US, able to show differences in hepatic venous opacification. However, most of these US signs are not pathognomonic, and therefore a multidisciplinary clinical reasoning must not be lacking. The aim of the present review is to easily provide US signs of liver alterations in HF, in particular right heart failure with volume overload, suggesting including liver US in instrumental diagnosis and therapeutic monitoring of HF.