The concept of wide versus narrow Pulse Pressure

[Ace3]

wide vs narrow pulse pressure...
plz can anyone explain....

[NGaleas]

Pulse Pressure is the difference between Systolic Pressure and Diastolic Pressure, for example: 120/80mmHg. Pulse Pressure would be: 120 - 80= 40.
This means that a pulse pressure doesn't gives you an idea of a normal pressure, because the same value (40mmHg) can be achieved if you have a patient with a pressure of 160/120. Several studies have identified that high (wide) pulse pressure: Causes more artery damage compared to high blood pressure with normal pulse pressure, indicates elevated stress on the left ventricle and is affected differently by different high blood pressure medicines.
USMLE wise, pulse pressure relation to the left ventricle is the most important aspect, since it helps you differentiate aortic regurgitation (high(wide) pulse pressure) and aortic stenosis (low(or narrow) pulse pressure.
Pulse pressure is high (or wide) in chronic aortic regurgitation because blood is coming back to the ventricle during diastole, increasing stress on the left ventricle.
Pulse pressure is low (or narrow) in aortic stenosis because not enough blood would be able to leave the left ventricle during systole, therefore, aortic pressure during systole is diminished.

[INCOGNITO]

@N
thnaks a lot for ur help
i like ur reply

[NGaleas]

Originally Posted by IKR123

@N
thnaks a lot for ur help
i like ur reply

You are welcome IKR123

[Ace3]

Originally Posted by NGaleas

Pulse Pressure is the difference between Systolic Pressure and Diastolic Pressure, for example: 120/80mmHg. Pulse Pressure would be: 120 - 80= 40.
This means that a pulse pressure doesn't gives you an idea of a normal pressure, because the same value (40mmHg) can be achieved if you have a patient with a pressure of 160/120. Several studies have identified that high (wide) pulse pressure: Causes more artery damage compared to high blood pressure with normal pulse pressure, indicates elevated stress on the left ventricle and is affected differently by different high blood pressure medicines.
USMLE wise, pulse pressure relation to the left ventricle is the most important aspect, since it helps you differentiate aortic regurgitation (high(wide) pulse pressure) and aortic stenosis (low(or narrow) pulse pressure.
Pulse pressure is high (or wide) in chronic aortic regurgitation because blood is coming back to the ventricle during diastole, increasing stress on the left ventricle.
Pulse pressure is low (or narrow) in aortic stenosis because not enough blood would be able to leave the left ventricle during systole, therefore, aortic pressure during systole is diminished.

thanks that was really helpful

[NGaleas]

You're welcome confident.
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

[Ace3]

Originally Posted by NGaleas

You're welcome confident.
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

thanks so much ...u made the concept very clear for me now...only one doubt left..i,e in AR most blood goes back into ventricle instead of going out in systole..so co should decrease=decrease systolic pressure=decr pp should be there. why pp is increasing?this causing me crazy

[NGaleas]

Remember that in aortic regurgitation, the blood flow coming back to the left ventricle occurs during diastole(during diastole aortic valve is closed, in aortic regurgitation the valve is insufficient to close).Diastolic reflux through the aortic valve can lead to left ventricular volume overload. So this would actually increase systolic stroke volume and lower diastolic aortic pressure,
An increase in systolic stroke volume and low diastolic aortic pressure produces an increased pulse pressure.

[Ace3]

Originally Posted by NGaleas

Remember that in aortic regurgitation, the blood flow coming back to the left ventricle occurs during diastole(during diastole aortic valve is closed, in aortic regurgitation the valve is insufficient to close).Diastolic reflux through the aortic valve can lead to left ventricular volume overload. So this would actually increase systolic stroke volume and lower diastolic aortic pressure,
An increase in systolic stroke volume and low diastolic aortic pressure produces an increased pulse pressure.

thanks for making concept crystal clear

[good_boy_1234]

Originally Posted by NGaleas

Remember that in aortic regurgitation, the blood flow coming back to the left ventricle occurs during diastole(during diastole aortic valve is closed, in aortic regurgitation the valve is insufficient to close).Diastolic reflux through the aortic valve can lead to left ventricular volume overload. So this would actually increase systolic stroke volume and lower diastolic aortic pressure,
An increase in systolic stroke volume and low diastolic aortic pressure produces an increased pulse pressure.

Thanks for explanation, I really like people who understand mechanism of action.

[leo lakhani]

Originally Posted by NGaleas

You're welcome confident.
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

what z reson behind increased diastolic pressure in mitral stenosis, in pathophysio q bank it z written bt i did nt understand, can u explain plz, thx.

[Ace3]

Originally Posted by leo lakhani

what z reson behind increased diastolic pressure in mitral stenosis, in pathophysio q bank it z written bt i did nt understand, can u explain plz, thx.

actually in ms when diameter of valve area deceases then impedance to flow occur--->gradient across valve area should increase-->so left ventricle filling volume decrease so diastolic volume and pressure decrease and most of volume retained in lft atrium so left atrial filling and volume increases-->as heart increases co and heart rate..more gradient and pressure builds up across mitral area so diastolic pressure in left ventricle should decrease becoz of decreases volume rite?

As the valve progressively narrows, the resting diastolic mitral valve gradient, and hence left atrial pressure, increases.

[NGaleas]

Originally Posted by leo lakhani

what z reson behind increased diastolic pressure in mitral stenosis, in pathophysio q bank it z written bt i did nt understand, can u explain plz, thx.

Remember that in mitral stenosis, during diastole the blood volume ejected to the left ventricle from the left auricle can't pass completely because of the stenotic mitral valve, so more blood is accumulated in the left auricle during diastole. This accumulated blood increases diastolic pressure.
Persistent LeftAtrial-LeftVentricle gradient in diastole leads to sustained flow throughout diastole. This persistent gradient increases left atrial pressure during diastole.

Limited flow into the Left Ventricle has 3 major sequale:
1.Elevation of Left Atrial pressure during diastole.
2.Secondary Right Ventricle pressure overload.(Can lead to pulmonary hypertension)
3.Reduced Left Ventricle ejection performance.

Due to diminished preload, tachycardic response to compensate the decreased stroke volume worsens the transmitral gradient.

[leo lakhani]

Originally Posted by confident

actually in ms when diameter of valve area deceases then impedance to flow occur--->gradient across valve area should increase-->so left ventricle filling volume decrease so diastolic volume and pressure decrease and most of volume retained in lft atrium so left atrial filling and volume increases-->as heart increases co and heart rate..more gradient and pressure builds up across mitral area so diastolic pressure in left ventricle should decrease becoz of decreases volume rite?

As the valve progressively narrows, the resting diastolic mitral valve gradient, and hence left atrial pressure, increases.

diastolic pressure in mitral stenosis increases not decreases

[Ace3]

Originally Posted by leo lakhani

diastolic pressure in mitral stenosis increases not decreases

Due to decreased flow due to MS --> decreased filling volume in left ventricle so-->diastolic pressure in ventricle decreases and distolic pressure across mitral valve and left atrium increases due to retaining of volume due to MS.
In above context i meant across left atrium and left atrial valve area...hope clarified.

[drzamzam]

In case of aortic stenosis aren't we supposed to have wide pulse pressure since more pressure is required to cause a change in volume (push blood during through stiff valve) in systole, and low blood volume in aorta in diastole thus lower diastolic pressure ??

[NGaleas]

Originally Posted by drzamzam

In case of aortic stenosis aren't we supposed to have wide pulse pressure since more pressure is required to cause a change in volume (push blood during through stiff valve) in systole, and low blood volume in aorta in diastole thus lower diastolic pressure ??

Pulse pressure is directly proportional to stroke volume, so, as you have established, if there is aortic stenosis, not too much blood would be ejected from the left ventricle, so stroke volume (and cardiac output)would be diminished, and therefore pulse pressure is diminished.
Normally, systolic pressure exceeds diastolic by about 40 mm Hg. Narrowed pressure—a difference of less than 30 mm Hg—occurs when peripheral vascular resistance increases, cardiac output declines, or intravascular volume markedly decreases.
Remember that pulse pressure doesn't refers to the pressure produced inside the left ventricle, it refers to the difference between systolic pressure and diastolic pressure.

Pulse pressure = Systolic pressure - Diastolic pressure = Stroke volume

SV= CO/HR

If you see the equation above, if cardiac output (CO) is decreased, stroke volume (SV) is decreased. (Cardiac output decreases in aortic stenosis)

Also you can calculate Stroke volume with: SV= EDV - ESV
Remember that in aortic stenosis end systolic volume is increased, so that would also explain why stroke volume decreases, and, therefore pulse pressure is decreased.

[drzamzam]

Originally Posted by NGaleas

Pulse pressure = Systolic pressure - Diastolic pressure = Stroke volume

Wonderful explanation thanks, but I didn't understand the relation between Pulse pressure and SV, why is pulse pressure = SV ?

[NGaleas]

Originally Posted by drzamzam

Wonderful explanation thanks, but I didn't understand the relation between Pulse pressure and SV, why is pulse pressure = SV ?

http://bme.usc.edu/bme403/Section_3/pulse_pressure.html

[drzamzam]

Originally Posted by NGaleas

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.

Awesome link thanks, 1 final question
How is cardiac output related to systolic pressure, and TPR related to diastolic pressure as you mentioned ?

[NGaleas]

Originally Posted by drzamzam

Awesome link thanks, 1 final question
How is cardiac output related to systolic pressure, and TPR related to diastolic pressure as you mentioned ?

Systolic pressure is the measure of blood pressure while your heart is beating (systole) (cardiac ouput).

Diastolic pressure is the measure of blood pressure when your heart is relaxed, this means diastolic pressure is the pressure in your blood vessels in between beating. (diastole) (TPR).


Imagine yourself measuring blood pressure to a patient, when you measure blood pressure, you take into account the first beat you hear as systolic pressure, and when the beating stops, the last measurement you noticed is the diastolic pressure.