per wavelength. This compares with
for the aorta.
Thus, greater attenuation and slower pulse wave propagation velocity are
found in the vena cava.
trains of high frequency small amplitude sinusoidal pulse
waves were imposed on the dog's abdominal vena cava. Attenuation is represented by
the amplitude ratio
as a function of changes
propagating distance as a fraction of
From Anliker et al.
The attenuation was attributed to the viscosity
blood, the radial
transmission to surrounding tissues and the viscoelastic properties
walls. This latter is the predominating factor, as have been found for the
systemic arteries by Li et al.
That the attenuation per wavelength
independent of frequency
suggest that the energy
dissipation is independent
strain rate. This study uses frequencies
much higher than the highest significant component of
natural pulse pressure and flow waveforms.
seen from the above experimental
measurements, is significantly lower in veins than in corresponding size
arteries. This can be measured as foot-to-foot velocity or can be readily
estimated from the Moens-Korteweg formula.
But with the changing cross-sectional area and the transmural
pressure, pulse wave velocity is seen to be dependent on both vessel