Highlights
- Wave components In order to distinguish each component of the hepatic vein waveform, some features may help in guiding. In physiologic states: - The A wave is taller than the V wave, with its peak above the baseline; the peak of the V wave may be above the line, on the line or below the line (transicional wave); - The A wave is larger than the V wave; - The S wave is larger than the D wave in most patients; - The S wave is deeper or is at the same level than the D wave – this is called a S ≥ D pattern. The A wave remains wider than the V wave in pathologic states, except in severe tricuspid regurgitation, in which there is a reversal of the S wave.
- Phasicity The presence of flow means that there is (some form of) phasicity. The triphasic patterncorresponds to a normal phasicity in the hepatic vein waveform. The absence of flow implies an absence of phasicity. The absence of phasicity is the typical finding of Budd-Chiari Syndrome with complete obstruction. Budd-Chiari Syndrome may also manifest as a wave with decreased phasicity if the obstruction is incomplete or with increased flow velocities and turbulence at the level of stenosis. Fig. 5: Spectral (A) and color Doppler (B) of a patient with chronic Budd-Chiari Syndrome as a vascular complication of hepatic amebic abscess. There are some venous segments with an absence of color flow (A). The spectral tracing of a segment with the presence of color flow shows a waveform with decreased phasicity (B). In the presence of phasicity, we can further classify it as having an increased phasicity (pulsatile wave) or decreased phasicity. There is an increased phasicity when both the antegrade and retrograde velocities are increased, resulting in taller retrograde waves and deeper antegrade waves. The diseases that commonly result in pulsatile waves are right-sided heart failure and tricuspid regurgitation. There is a decreased phasicity when the both the antegrade and retrograde velocities are decreased, resulting in shorter retrograde waves and less deep antegrade waves. The classic example of decreased phasicity is the presence of hepatic cirrhosis. A normal liver easily adapts to the changing pressure waves, producing a normal waveform. In the presence of hepatic fibrosis, the veins lose their ability to accommodate retrograde flow, resulting in a decreased phasic oscillation (figure 6). Hepatic masses, ascites or other causes of raised intra-abdominal pressuremay also result in dampening of the waveform. Fig. 6: Spectral Doppler of a patient with hepatitis C-related liver cirrhosis shows a hepatic vein waveform with a monophasic pattern.
- The primary abnormality in right heart failure, as long as the tricuspid valve remains competent, is an excessive volume of blood in the right cardiac chambers. This will cause a larger volume of blood toward the IVC and HVs during atrial systole and ventricular systole, manifesting in spectral Doppler tracing as taller A and V.
- The typical finding of the hepatic venous waveform in constrictive pericarditis is an extra retrograde wave before the A wave caused by premature attainment of the maximum capacity of the right atrium. Since the A wave is also retrograde, the two will together form a W-shaped wave form – W wave pattern (figure 16). Fig. 16: Scheme demonstrating the features of the Doppler waveform in constrictive pericarditis and their underlying mechanism. Figure 17 illustrates a diagram and a spectral Doppler of a characteristic waveform in constrictive pericarditis. Fig. 17: Diagram (left) and spectral Doppler (right) of a typical waveform in constrictive pericarditis. It should be noted that in this tracing the S wave is slightly less deep that the D wave. This patient had also a echocardiographically proven mild tricuspid regurgitation.
Highlights
- Wave components In order to distinguish each component of the hepatic vein waveform, some features may help in guiding. In physiologic states: - The A wave is taller than the V wave, with its peak above the baseline; the peak of the V wave may be above the line, on the line or below the line (transicional wave); - The A wave is larger than the V wave; - The S wave is larger than the D wave in most patients; - The S wave is deeper or is at the same level than the D wave – this is called a S ≥ D pattern. The A wave remains wider than the V wave in pathologic states, except in severe tricuspid regurgitation, in which there is a reversal of the S wave.
- Phasicity The presence of flow means that there is (some form of) phasicity. The triphasic patterncorresponds to a normal phasicity in the hepatic vein waveform. The absence of flow implies an absence of phasicity. The absence of phasicity is the typical finding of Budd-Chiari Syndrome with complete obstruction. Budd-Chiari Syndrome may also manifest as a wave with decreased phasicity if the obstruction is incomplete or with increased flow velocities and turbulence at the level of stenosis. Fig. 5: Spectral (A) and color Doppler (B) of a patient with chronic Budd-Chiari Syndrome as a vascular complication of hepatic amebic abscess. There are some venous segments with an absence of color flow (A). The spectral tracing of a segment with the presence of color flow shows a waveform with decreased phasicity (B). In the presence of phasicity, we can further classify it as having an increased phasicity (pulsatile wave) or decreased phasicity. There is an increased phasicity when both the antegrade and retrograde velocities are increased, resulting in taller retrograde waves and deeper antegrade waves. The diseases that commonly result in pulsatile waves are right-sided heart failure and tricuspid regurgitation. There is a decreased phasicity when the both the antegrade and retrograde velocities are decreased, resulting in shorter retrograde waves and less deep antegrade waves. The classic example of decreased phasicity is the presence of hepatic cirrhosis. A normal liver easily adapts to the changing pressure waves, producing a normal waveform. In the presence of hepatic fibrosis, the veins lose their ability to accommodate retrograde flow, resulting in a decreased phasic oscillation (figure 6). Hepatic masses, ascites or other causes of raised intra-abdominal pressuremay also result in dampening of the waveform. Fig. 6: Spectral Doppler of a patient with hepatitis C-related liver cirrhosis shows a hepatic vein waveform with a monophasic pattern.
- The primary abnormality in right heart failure, as long as the tricuspid valve remains competent, is an excessive volume of blood in the right cardiac chambers. This will cause a larger volume of blood toward the IVC and HVs during atrial systole and ventricular systole, manifesting in spectral Doppler tracing as taller A and V.
- The typical finding of the hepatic venous waveform in constrictive pericarditis is an extra retrograde wave before the A wave caused by premature attainment of the maximum capacity of the right atrium. Since the A wave is also retrograde, the two will together form a W-shaped wave form – W wave pattern (figure 16). Fig. 16: Scheme demonstrating the features of the Doppler waveform in constrictive pericarditis and their underlying mechanism. Figure 17 illustrates a diagram and a spectral Doppler of a characteristic waveform in constrictive pericarditis. Fig. 17: Diagram (left) and spectral Doppler (right) of a typical waveform in constrictive pericarditis. It should be noted that in this tracing the S wave is slightly less deep that the D wave. This patient had also a echocardiographically proven mild tricuspid regurgitation.