The concept of wide versus narrow Pulse Pressure - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     55,019 Members     239,296 Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 07-01-2011
Ace3's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 734
Threads: 88
Thanked 278 Times in 188 Posts
Reputation: 290
Heart The concept of wide versus narrow Pulse Pressure

wide vs narrow pulse pressure...
plz can anyone explain....
Reply With Quote
The above post was thanked by:
INCOGNITO (07-03-2011)



  #2  
Old 07-01-2011
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 124
Threads: 5
Thanked 186 Times in 67 Posts
Reputation: 196
Default Pulse Pressure

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.

Last edited by NGaleas; 07-01-2011 at 02:17 PM. Reason: type error
Reply With Quote
The above post was thanked by:
Ace3 (07-03-2011), dr.muhamad (07-02-2011), Drothman2010 (07-05-2011), Hamada (07-05-2014), INCOGNITO (07-01-2011), J.Rodriguez (07-04-2011), Krazy (11-21-2013), leo lakhani (07-04-2011), MANIAKOS (07-01-2011), Mashee (07-01-2011), Meli (07-10-2011), mzee74 (07-03-2011), orfie25 (07-04-2011), pass7 (07-03-2011), prepink (07-01-2011), skido (07-04-2011), Taiwan_Guy (07-04-2011), usluipek (07-30-2011)
  #3  
Old 07-01-2011
INCOGNITO's Avatar
USMLE Forums Guru
 
Steps History: Step 1 Only
Posts: 343
Threads: 127
Thanked 508 Times in 190 Posts
Reputation: 518
Default

@N
thnaks a lot for ur help
i like ur reply
Reply With Quote
  #4  
Old 07-01-2011
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 124
Threads: 5
Thanked 186 Times in 67 Posts
Reputation: 196
Default

Quote:
Originally Posted by IKR123 View Post
@N
thnaks a lot for ur help
i like ur reply
You are welcome IKR123
Reply With Quote
The above post was thanked by:
INCOGNITO (07-03-2011)
  #5  
Old 07-03-2011
Ace3's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 734
Threads: 88
Thanked 278 Times in 188 Posts
Reputation: 290
Default

Quote:
Originally Posted by NGaleas View Post
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
Reply With Quote
  #6  
Old 07-03-2011
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 124
Threads: 5
Thanked 186 Times in 67 Posts
Reputation: 196
Default Other fun facts about pulse pressure

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
Reply With Quote
The above post was thanked by:
Ace3 (07-03-2011), Ammara (10-22-2013), devareddy (03-25-2014), drnrpatel (07-30-2011), INCOGNITO (07-03-2011), Meli (07-10-2011), mzee74 (07-03-2011), pass7 (07-03-2011), Pharoah9 (02-27-2014), Taiwan_Guy (07-04-2011)
  #7  
Old 07-03-2011
Ace3's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 734
Threads: 88
Thanked 278 Times in 188 Posts
Reputation: 290
Default

Quote:
Originally Posted by NGaleas View Post
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
Reply With Quote
  #8  
Old 07-03-2011
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 124
Threads: 5
Thanked 186 Times in 67 Posts
Reputation: 196
Default Aortic regurgitation or Aortic insufficiency

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.
Reply With Quote
The above post was thanked by:
Ace3 (07-03-2011), INCOGNITO (07-03-2011), Meli (07-10-2011), pkul85 (08-25-2013)
  #9  
Old 07-03-2011
Ace3's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 734
Threads: 88
Thanked 278 Times in 188 Posts
Reputation: 290
Default

Quote:
Originally Posted by NGaleas View Post
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
Reply With Quote
  #10  
Old 07-03-2011
good_boy_1234's Avatar
USMLE Forums Master
 
Steps History: 1 + CS
Posts: 541
Threads: 91
Thanked 279 Times in 141 Posts
Reputation: 325
Default

Quote:
Originally Posted by NGaleas View Post
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.
Reply With Quote
  #11  
Old 07-04-2011
USMLE Forums Scout
 
Steps History: Step 1 Only
Posts: 28
Threads: 0
Thanked 5 Times in 5 Posts
Reputation: 15
Default d

Quote:
Originally Posted by NGaleas View Post
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.
Reply With Quote
  #12  
Old 07-04-2011
Ace3's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 734
Threads: 88
Thanked 278 Times in 188 Posts
Reputation: 290
Default

Quote:
Originally Posted by leo lakhani View Post
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.
Reply With Quote
The above post was thanked by:
INCOGNITO (07-04-2011), leo lakhani (07-10-2011)
  #13  
Old 07-04-2011
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 124
Threads: 5
Thanked 186 Times in 67 Posts
Reputation: 196
Default Mitral Stenosis increased diastolic pressure

Quote:
Originally Posted by leo lakhani View Post
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.
Reply With Quote
The above post was thanked by:
leo lakhani (07-10-2011), Meli (07-10-2011)
  #14  
Old 07-10-2011
USMLE Forums Scout
 
Steps History: Step 1 Only
Posts: 28
Threads: 0
Thanked 5 Times in 5 Posts
Reputation: 15
Default d

Quote:
Originally Posted by confident View Post
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
Reply With Quote
  #15  
Old 07-10-2011
Ace3's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 734
Threads: 88
Thanked 278 Times in 188 Posts
Reputation: 290
Default

Quote:
Originally Posted by leo lakhani View Post
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.
Reply With Quote



  #16  
Old 07-30-2011
USMLE Forums Addict
 
Steps History: Not yet
Posts: 135
Threads: 29
Thanked 5 Times in 5 Posts
Reputation: 15
Help Low PP at aortic stenosis ????

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 ??
Reply With Quote
  #17  
Old 07-30-2011
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 124
Threads: 5
Thanked 186 Times in 67 Posts
Reputation: 196
Default Pulse pressure and Stroke Volume

Quote:
Originally Posted by drzamzam View Post
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.
Reply With Quote
  #18  
Old 07-30-2011
USMLE Forums Addict
 
Steps History: Not yet
Posts: 135
Threads: 29
Thanked 5 Times in 5 Posts
Reputation: 15
Help

Quote:
Originally Posted by NGaleas View Post

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 ?
Reply With Quote
  #19  
Old 07-30-2011
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 124
Threads: 5
Thanked 186 Times in 67 Posts
Reputation: 196
Default Stroke Volume and Pulse Pressure

Quote:
Originally Posted by drzamzam View Post
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
Reply With Quote
  #20  
Old 07-30-2011
USMLE Forums Addict
 
Steps History: Not yet
Posts: 135
Threads: 29
Thanked 5 Times in 5 Posts
Reputation: 15
Help

Quote:
Originally Posted by NGaleas View Post
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 ?
Reply With Quote
  #21  
Old 07-30-2011
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 124
Threads: 5
Thanked 186 Times in 67 Posts
Reputation: 196
Default Systolic and Diastolic Pressure

Quote:
Originally Posted by drzamzam View Post
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.
Reply With Quote



Reply

Tags
Cardiovascular-, Physiology-

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pulse Pressure and Vessel Compliance bronchiole USMLE Step 1 Forum 8 07-30-2011 09:26 AM
Wide, fixed, paradoxical splitting of S2 Ace3 USMLE Step 2 CK Forum 3 06-20-2011 07:18 AM
pressure system of lung; pneumothorax versus normal Ace3 USMLE Step 2 CK Forum 2 05-25-2011 05:50 AM
Glaucoma Concept. donofitaly USMLE Step 1 Forum 1 02-19-2011 03:59 PM
mechanism for elevated pulse rate khushboo USMLE Step 1 Forum 14 09-16-2010 08:30 AM

RSS Feed
Find Us on Facebook

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)