Peripheral circulation
Pulse pressure
Pulse pressure is dependent on arterial compliance and stroke volume
Stroke volume increases systolic pressure more than it raises diastolic pressure
--> Increased pulse pressure
* [BL8:p146]
Reduced compliance
--> Increased pulse pressure given the same stroke volume
Vascular compliance is less distally than proximally.
Velocity of pressure wave is inversely related to compliance
Waveform changes
[BL8:p149; KB2:p101-102]
- Damping - high frequency components are damped out and disappear as wave travels distally.
- Systolic change - systolic portions of the pressure wave become narrowed and elevated.
- Diastolic change - a hump may appear on the diastolic portion of the pressure wave.
- Slight delay of onset, but not much, because pressure waves travels must faster than blood itself.
Thus, waveform at radial pulse:
- Taller
- Narrower at its peak
- No incisura
- Often a diastolic hump
Notes:
- In elderly, pulse pressure may be transmitted virtually unchanged
