Pulsatile flow in the hepatic veins

Pulsatile flow in the hepatic veins
Pulsatile flow in the hepatic veins refers to the rhythmic, wave-like movement of blood seen during Doppler ultrasound assessment, typically influenced by right heart activity. Here's a breakdown to help you understand what it means and when it's considered normal or abnormal:
Normal Physiology

• Hepatic veins drain blood from the liver into the inferior vena cava (IVC), and then into the right atrium.
• Because of this direct connection to the heart, the hepatic vein waveform is normally pulsatile, reflecting the phasic pressure changes in the right atrium during the cardiac cycle.

Normal hepatic vein Doppler waveform includes:
1. S wave (ventricular systole): Blood flows into the right atrium (dominant wave).

Ultrasound image demonstrating the S wave (ventricular systole) in a normal hepatic vein Doppler waveform. S wave: The first downward deflection below the baseline, occurring during ventricular systole. It represents the antegrade flow of blood from the hepatic veins into the right atrium and inferior vena cava.
2. D wave (early diastole): Blood continues to flow during atrial relaxation.

D wave: The subsequent upward deflection, occurring during early diastole, indicating continued antegrade flow.

3. A wave (atrial contraction): Brief reversal or slowing of flow.
A wave: The small upward deflection above the baseline, occurring during atrial systole. It represents the brief retrograde flow of blood from the right atrium into the hepatic veins due to atrial contraction.
Increased pulsatility or abnormal patterns may indicate:

• Tricuspid regurgitation: Enlarged retrograde "A" wave.

showing an enlarged retrograde A wave (atrial contraction), often seen as a prominent upward deflection above the baseline during atrial systole.
Retrograde "A" Wave: Enlarged and above the baseline—indicates elevated right atrial pressure during atrial contraction, which occurs with significant tricuspid regurgitation.
Diminished/Reversed "S" Wave: In systole, instead of forward (antegrade) flow, you may see decreased or even reversed flow (above the baseline), a hallmark of regurgitant blood flowing back into the hepatic veins via the incompetent tricuspid valve.
Tall "V" Wave: May also be observed, due to elevated atrial pressure from volume overload.
Tips for Clinical Acquisition
• Use a subcostal or right upper quadrant window aligned with the hepatic veins.
• Employ pulsed-wave Dopplerjust proximal to the IVC.
• Always include an ECG trace—helps differentiate A, S, V, D waves accurately.
• Right heart failure or constrictive pericarditis: Exaggerated pulsatility or flow reversal.
Hepatic vein Doppler ultrasound images illustrating exaggerated pulsatility and flow reversal seen in right heart failure or constrictive pericarditis:

Image Interpretation
A-Triphasic “W-wave” pattern

• These tracings show retrograde S-wave dips and prominent diastolic reversal (D-wave) before atrial contraction.
• They form a distinctive “W” shape—highly specific for constrictive pericarditis (100% specificity)

B-Respiratory variation in flow

• The hepatic vein flow demonstrates pronounced diastolic flow reversal during expiration, reflecting impaired RV filling due to pericardial restraint
• Forward flow peaks during inspiration, while expiration induces reversal—classic of constrictive physiology

C-Elevated hepatic vein diastolic reversal ratio
• Quantitative studies show a reversal / forward flow ratio ≥ 0.79 is highly specific (≈91%) for constrictive pericarditis
D-Distinguishing from right heart failure with TR In isolated severe TR or RV failure, you get systolic-only reversal, but the respiratory-dependent diastolic reversal is more typical of pericardial constriction
• Pericardial tamponade

1. Large circumferential pericardial effusion

• Anechoic (black) space surrounding the heart in parasternal (top-left) and subxiphoid/apical (top-right) views

2. Right atrial systolic collapse

• RA wall indents inward during systole—an early, specific sign of tamponade

3. Right ventricular diastolic collapse

• RV free wall inverts during early diastole, often visualized in PLAX or subxiphoid views. Confirmed via 2D or M-mode

4. ‘Swinging heart’ phenomenon


Transthoracic echocardiogram images demonstrating the classic “swinging heart” phenomenon in large pericardial effusion, typical of cardiac tamponade.
Large circumferential pericardial effusion: Notice the prominent black (anechoic) space surrounding the heart in apical and parasternal views.
Swinging motion of the heartThe heart visibly swings within the fluid-filled sac—this oscillatory movement results from the heart “floating” in a large effusion.
Chamber collapseLook closely for signs like right ventricular diastolic collapse and right atrial systolic collapse, early and specific indicators of tamponade.
Associated findings
1. A plethoric IVC with minimal respiratory collapse.
2. Electrical alternans on ECG, a consequence of swinging heart motion.

Why It Matters

• Swinging heart is highly specific for large pericardial effusion.
• However, the diagnosis of tamponade is clinical, requiring hemodynamic compromise (e.g., hypotension, elevated JVP) plus echo signs like chamber collapse.
• Prompt recognition and management, including urgent pericardiocentesis, is critical and life-saving.


• Severe pulmonary hypertension
key features of severe pulmonary hypertension (PH)
1. Right Ventricle (RV) Dilatation & Hypertrophy

• Parasternal and apical 4‑chamber views (e.g., bottom-left images) show a grossly enlarged RV often exceeding LV size—sign of chronic pressure overload.
• RV free-wall thickening >5 mm and chamber enlargement indicate hypertrophy.
2. Interventricular Septum Flattening (“D‑sign”)

• In short-axis PLAX or PSAX views, the septum bows toward the LV, creating a “D-shaped” LV—a classic marker of RV pressure overload.
• Pulmonary Valve M‑Mode Abnormalities
• Loss of normal “a‑dip” and the presence of mid‑systolic notching (“flying W”) on the pulmonic valve M‑mode signal severe PH.
• Continuous-Wave Doppler of TR Jet
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Decreased pulsatility or flat flow may suggest:
• Cirrhosis / liver fibrosis: Loss of compliance of liver parenchyma dampens the pulsatility.
• Hepatic vein thrombosis (Budd-Chiari syndrome)
Clinical Use of Hepatic Vein Doppler

• Assessing volume status and right heart function.
• Evaluating liver congestion or fibrosis.
• Diagnosing cardiac causes of liver dysfunction.

Waveform Type	Pattern	Description	Associated Conditions
Triphasic	S > D > A	Normal pattern. Two antegrade (S, D) and one retrograde (A) wave.	Normal physiology
Biphasic	S and D only (reduced A)	Loss of retrograde A wave. Less pulsatile.	Early liver disease, IVC compression
Monophasic	Flat, low variability	Continuous non-pulsatile flow.	Cirrhosis, hepatic congestion, Budd-Chiari
Reversed S Wave	S above baseline	Retrograde systolic flow.	Tricuspid regurgitation, right heart failure
Prominent A Wave	Tall retrograde A wave	Exaggerated atrial contraction flow reversal.	Tricuspid stenosis, atrial stiffness