Which statement best describes pulse pressure and arterial stiffness?

• A. Pulse pressure equals mean arterial pressure; arterial stiffness decreases pulse pressure.
• B. Pulse pressure equals heart rate; arterial stiffness has no effect.
• C. Pulse pressure equals stroke volume; arterial stiffness reduces.
• D. Pulse pressure equals SBP minus DBP; arterial stiffness increases pulse pressure for a given stroke volume.

Answer: (D)

Pulse pressure reflects the pressure swing with each beat and depends on how easily the arteries stretch. It is defined as the difference between systolic pressure (SBP) and diastolic pressure (DBP), not mean arterial pressure or heart rate, and while stroke volume influences the magnitude of the pressure rise, pulse pressure is not simply equal to stroke volume.

When arteries become stiffer, their ability to expand during systole is reduced (decreased compliance). For a given stroke volume, the heart ejects into a less compliant system, so systolic pressure rises more than diastolic pressure falls or remains steady, producing a larger difference between SBP and DBP. Thus arterial stiffness increases pulse pressure for a given stroke volume.