In Hepatic Veins 101,  we discussed the structure, function and waveforms of the hepatic veins, in regards to the cardiac cycle. This blog will cover how the hepatic veins play a role with the right heart. We tend to forget about the importance and useful information the hepatic veins provide us.  Lets review, how the hepatic veins play a role in:

• Tricuspid regurgitation (TR)
• Right heart failure

Tricuspid Regurgitation

The hepatic vein waveform can be reflective on the severity of TR present. The more severe the regurgitation, the more pulsatile the waveform becomes.

Waveform Criteria:

• Pulsatile waveform
• Tall A-wave & V-wave
• Decreased or Reversed S-Wave
• D-Wave < S-Wave

Let’s breakdown the waveform process during the cardiac cycle when tricuspid regurgitation is present….

A scale was developed based upon the waveform pattern of the hepatic veins to help with adding more data to assess the severity of TR:

Right Heart Failure

The hepatic vein waveform can also show indications of right heart failure! The change in waveforms are similar to tricuspid regurgitation…

Right Heart Failure Criteria:

• Pulsatile waveform
• Tall A-wave & V-wave
• Normal relationship between S-wave & D-wave (S > D)
• S-wave will never become retrograde (in absence of TR)

Combined Tricuspid Regurgitation & Right Heart Failure

In some cases, where the patient has both TR and right heart failure, the hepatic waveforms can become biphasic.

• Single retrograde wave per cardiac cycle
• Single antegrade wave per cardiac cycle

In severe cases, the waveforms can fused into one retrograde wave with an antegrade D-wave.

Items to Note:

• Hepatic vein waveforms look the same for both Mild TR and for right heart failure (both can have type 1 or 2 waveform patterns)
• Retrograde S-wave present = some degree of TR is present

Hepatic Vein Systolic Filling Fraction

A ratio of the velocity-time integrals (VTI’s) of the S-wave and sum of both S-wave and D-wave (the ratio excludes the A-wave).

<55% =RAP > 8 mmHg

• Sensitivity and specificity of 90%
• Tested with patients on ventilators & proved useful when averaging 5 or more beats!
• Higher the RAP = Decrease in Systolic Filling Fraction

Vs/Vd Hepatic Vein Ratio

By measuring the velocity of the S-wave and D-wave, we can obtain a simple ratio to help indicate if an elevated RAP is present.

Vs/Vd < 1 = Elevated RAP

• Higher the right atrial pressure (RAP), the lower the pressure gradient (PG) between hepatic veins/IVC and right atrium
• S-wave diminishes due to decrease of systolic flow
• D-Wave (Vd) Dominant

Let’s take a look at this image below:

• On the left, a normal waveform pattern is demonstrated showing S/D >1
• One the right, an abnormal waveform pattern is demonstrated showing S/D <1
  • Indication of elevated RAP

Conclusion

Now that we have learned both the basics of hepatic veins and the relativity in regards to the heart, we can now implement evaluation of these veins when indicated during our echocardiograms! Here are a few helpful tips to take away…..

1. Hepatic veins are useful for determining RAP when the IVC is unable to assess for collapsibility
2. Hepatic vein waveform can help determine severity of TR and presence of right heart failure
3. Pulsed Doppler the hepatic vein at close proximity to IVC
4. Dilated hepatic veins (>10mm) can indicate right heart failure and TR
5. Hepatic veins can be useful in diagnoising additional pathology, in additional to TR and right heart failure
6. If >moderate TR present, evaluate the hepatic veins

We hope you enjoyed our right heart blog series!

• Introduction to Right Heart Assessment
• 7 Tips to Implementing to Implementing RV Size Quantification
• 10 Tips to Correct RA Size Quantification
• 8 Tips to Correct RV Function Assessment with TAPSE and S’ Wave
• TAPSE and RVSP – Prognostic Value When Viewed as an Index
• 5 Things to Know about Using Fractional Area Change (FAC) to Assess RV Function
• RIMP to assess RV Function – What is RIMP?
• 6 Tips for Calculating RVSP
• 8 Things to Know About the Estimation of RAP
• Hepatic Veins – 101
• Hepatic Veins & Right Heart Abnormalities

Want a CME for reading this blog? Click below to access CardioServ’s online CME platform offering Cat. 1 AMA CMEs!

Andrea Fields MHA, RDCS

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References:

Scheinfield, M. H., MD, Bilali, A., ARDMS, & Koenigsberg, M., MD. (2009). Understanding the Spectral Doppler Waveform of the Hepatic Veins in Health and Disease. RadioGraphics,29, 2081-2098. Retrieved May 31, 2017, from http://pubs.rsna.org/doi/pdf/10.1148/rg.297095715

Rudski, L. G., MD. (2010). Guidelines for Echocardiographic Assessment of the Right Heart in Adults: A Report from the American Society of Echocardiography. JASE, 23, 685-713.