Imaging portal venous flow to aid assessment of right ventricular dysfunction

Excerpt

Pulsatile portal venous blood flow is a sign of portal hypertension originally described as a sign of severity in patients with congestive heart failure (CHF) (Figure). In this population, it is associated with increased central venous pressure (CVP), worse functional class, and elevated bilirubin, suggesting an impairment in liver function from venous congestion. Portal hypertension resulting from CHF begins with an elevation of the CVP and dilatation of the inferior vena cava (IVC) including its main tributaries such as the hepatic veins. When the dilatation becomes severe, the venous compliance of the IVC is decreased and pressure variations occurring in the right atrium during the cardiac cycle are transmitted through the hepatic sinusoids to the portal system. This results in a decrease in velocities in the portal system or, when severe, in a complete absence or reversal of portal flow during the period of the cardiac cycle corresponding to the v wave on the CVP waveform. Accordingly, Doppler evaluation of the portal flow could be used as a marker of end-organ venous congestion.

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