Measurement of pulse
wave velocity (XII.)
DEP. OF PHYSIOLOGY, FAC. OF MEDICINE, MU, 2015 © JANA HRUŠKOVÁ
Definition of pulse wave
• Pulse wave arises during heart revolution, when blood is ejected.
• Single pulse is propagated in arterial wall through the whole arterial system
Pulse wave curve
Pulse wave is composed of two waves: forward
traveling wave and backward traveling wave.
Forward wave travels from the heart to periphery.
Backward wave is rebounded from bifurcations of
arteries in periphery. It travels to the heart,
interferes with forward wave and both together
form shape of the pulse wave curve.
Amplitude of pulse wave increases in periphery
due to increased pulse wave velocity.
The shape of the curve is depend on the place
where it is measured. The smallest amplitude is
common in radial artery, greatest one in dorsal
pedis artery.
Backward traveling wave
Forward traveling wave
Pulse wave in aorta
Pulse wave in periphery
Heart
Periphery
Pulse wave velocity (PWV)
• Velocity of pulse wave propagation varies from 6 m/s (in aorta) to 20 m/s (in periphery)
• It is much greater than velocity of blood flow (0.8 – 1.0 m/s)
Factors affecting the pulse wave velocity
◦ Age
◦ Sex
◦ Genetic load
◦ Blood pressure
◦ Smoking
◦ Obesity
◦ Diabetes
◦ Dyslipidaemia
Changes of pulse wave in elderly people
Increased PWV and vanishing of typical characteristics of shape of the pulse
wave due to:
1. Increased arterial stiffness
2. Increased blood pressure
Changes of pulse wave in children
Increased PVW and vanishing of typical characteristics of shape of the pulse
wave due to:
1. Smaller length of arterial system
2. Longer ejection time
• Relatively long ejection time to small body and higher heart rate
leads to changes of summation of consecutive pulse waves
Normal values of PWV
Reference intervals for carotid-femoral index (PWV)
If the measured value is higher than 90. percentile for the age, it is the sign of cardiovascular pathology
(such as atherosclerosis) and such person has significant higher risk for cardiovascular diseases.
Measurement of PWV
1. Direct method
◦ Catheterisation
2. Indirect methods
◦ Ultrasonography
◦ Sphygmography
◦ Bioimpedance analysis
Sphygmography
For estimation of PWV, it is necessary to record
pulse wave in two different places (on two
arteries) and ECG simultaneously.
The carotid-femoral index – the PWV estimated
between carotid and femoral artery – is a marker
of aortic stiffness.
It is important to take in consideration values of
blood pressure. Higher blood pressure increased
arterial stiffness and therefore PWV is also
increased.
A B
T1 T2
d
PWV= d/ (T2-T1)
A B
T (T1, T2) – transition time – time from peak of R on ECG
and beginning of pulse wave
d – distance between registration points