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]

1. Damping - high frequency components are damped out and disappear as wave travels distally.
2. Systolic change - systolic portions of the pressure wave become narrowed and elevated.
3. Diastolic change - a hump may appear on the diastolic portion of the pressure wave.
4. 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