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What is pulse volume and what are its alterations?

What is volume of the pulse?
It is the amplitude of the pulse wave or the excursion felt at the wrist and usually reflects the pulse pressure (systolic BP minus diastolic BP), It depends on two factors :
  • Stroke volume
  • Compliance of the arteries.
The carotid, brachial or femoral arteries are more useful for assessing pulse volume and character
than the radial pulse. Normal pulse pressure is 30-60 mm of Hg.

What is pulse pressure and mean pressure?
Pulse pressure is the difference between systolic and diastolic BP (It roughly reflects the volume of the pulse). Mean pressure is approximately the arithmetic mean of diastolic and systolic pressure, and it Is calculated by diastolic pressure plus 1 /3rd of pulse pressure.
When pulse pressure is between 30 to 60mm of Hg pulse volume is normal.
When pulse pressure is less than 30 mm Hg, it is a small volume pulse.
When pulse pressure is greater than 60 mm Hg, it is a large volume pulse.

What are the clinical abnormalities in pulse volume?
  • Low volume pulse
  • High volume pulse
  • Varying volume
  • Pulsus alternans
  • Pulsus paradoxus
What are the causes of pulse with varying volume?
Varying volume of pulse is due to a combination of low, normal, or high volume pulse in varying manner as a result of varying duration of diastolic filling.
Atrial fibrillation - varying volume with irregular pulse - total irregularity of pulse.
Ventricular tachycardia - varying volume with regular pulse.
Atrial support to ventricular filling is variable.