Jul 30 2011
93 notes

Q

Amplify’d from www.usmle-forums.com
Remember PP is the difference between systolic pressure and diastolic pressure, since Cardiac output is related to systolic pressure, any time CO is increased pulse pressure will increase, and TPR is related to diastolic pressure, any time TPR is decreased pulse pressure will also increase.

For example, in anemia, resistance is diminished because of reduced viscosity (R=Vl/r4), so TPR is decreased.
In order to compensate anemic patients increase their cardiac output(increase both heart rate and stroke volume).
So MAP= CO (systolic pressure)increased x TPR (diastolic pressure) decreased
Pulse pressure= Systolic Pressure(increased) - Diastolic pressure (decreased)
The result would be a wide or high pulse pressure.

Other changes in pulse pressure include:
Increased pulse pressure: Aortic regurgitation, Aortic sclerosis
Decreased pulse pressure: Aortic stenosis, Mitral stenosis
Increased diastolic pressure: Mitral stenosis
Decreased diastolic pressure: Aortic regurgitation, Patent ductus arteriosus
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