Severity of MITRAL STENOSIS? - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     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 02-01-2011
USMLE Forums Addict
 
Steps History: 1 + CK
Posts: 109
Threads: 26
Thanked 32 Times in 14 Posts
Reputation: 42
Send a message via Skype™ to shaan.medico
Heart Severity of MITRAL STENOSIS?

1) the shorter the A2 Opening Snap duration the greater the the severity of stenosis?!
don't you people think that if severity is more, it will take more time for the mitral valve to open in diastole? and hence LONGER the opening snap ???


2) the greater the left atrial end diastolic press the lesser the severity of stenosis???
Isn't it like this that greater the severity, lesser blood will leave left atrium and greater the end daistolic left atrial press. ?


Please somebody explain these points........


thnx in advance................
Reply With Quote Quick reply to this message



  #2  
Old 02-01-2011
KaleKaleo's Avatar
USMLE Forums Scout
 
Steps History: Step 1 Only
Posts: 28
Threads: 2
Thanked 17 Times in 9 Posts
Reputation: 27
Arrow Explanation

1) the more stenosed the valve, the smaller the diameter, the shorter duration it needs to close, the shorter will be the opening snap.

2) the more left atrial end diastolic pressure, the more forces pushing blood from the LA to the LV at the end of diastole and therefore the less effects you have of a stenosed valve
Reply With Quote Quick reply to this message
The above post was thanked by:
Mondoshawan (02-01-2011), satrun (10-19-2016), shaan.medico (02-01-2011), tomymajor (02-02-2011)
  #3  
Old 02-01-2011
USMLE Forums Newbie
 
Steps History: Not yet
Posts: 9
Threads: 0
Thanked 20 Times in 7 Posts
Reputation: 30
Default

I think that the pathophysiology of mitral stenosis is based on the fact that it does not allow the blood to pass from left atrium to left ventricle.

So, using logic...

1) In a stenosis, blood accumulates in the atrium and enhances its pressure. Because heart is able to remodeling and dilating its cavities, there may be an atrium enlargement, thus decreasing pressure (that will still be enhanced).


2) Mitral valve opens when left atrium pressure is greater than left ventricle pressure. Since a mitral stenosis patient has an increased left atrium pressure, his valve will open before a normal valve. And, as the end-diastolic left atrium pressure increases (and, thus, the severity of mitral stenosis), the valve opens even earlier.


Actually, the diagnostic tools for mitral valve stenosis use the pressure as a criteria...

A normal person has a valve with 4-6cm² and gradient pressure <5mmHg.

A mitral stenosis has a valve with 1,5-2,5cm² and gradient pressure 5-10 mmHg.

A moderate mitral stenosis has a valve with 1,0-1,5cm² and gradient pressure 10-15 mmHg.

A severe mitral stenosis has a valve with <1,0cm² and gradient pressure >15 mmHg.



Sorry for not-english-speaker mistakes. I hope I helped you.

Last edited by GGossling; 02-01-2011 at 05:36 AM. Reason: New information.
Reply With Quote Quick reply to this message
The above post was thanked by:
drkanthiomc (10-31-2013), Mondoshawan (02-01-2011), satrun (10-19-2016), shaan.medico (02-01-2011)
 
  #4  
Old 02-01-2011
USMLE Forums Addict
 
Steps History: 1 + CK
Posts: 109
Threads: 26
Thanked 32 Times in 14 Posts
Reputation: 42
Send a message via Skype™ to shaan.medico
Default

from the discussion here, i only got tht severity of mitral stenosis also causes incr left end diastolic press. , so they are the same things, also both of them are related in the same way and by the same mechanism to A2-OS duration, bt how they are related is still a doubt for me????


OR i can say the other way round that, how a more stenosed valve opens earlier than a less stenosed valve?????
Reply With Quote Quick reply to this message
  #5  
Old 02-01-2011
USMLE Forums Newbie
 
Steps History: Not yet
Posts: 9
Threads: 0
Thanked 20 Times in 7 Posts
Reputation: 30
Default

All valves have the same opening mechanism:

Tricuspid opens when the right atrium pressure is greater than right ventricle pressure.

Aortic opens when the left ventricle pressure is greater than aortic pressure.


Mitral opens when left atrium pressure is greater than left ventricle pressure.



The more stenosed the valve is, the greater the atrium pressure, and that's the mechanism that causes the A2 - opening snap sound to be related with severity of disease.

After systole, A2 closes when aortic pressure is greater than left ventricle pressure. After that, ventricle enters in "diastasis" phase, when muscle is relaxing and decreasing its pressure as a consequence, without being filled. Diastasis is over when mitral valve opens, in other words, when atrium pressure becomes greater than ventricle pressure.

So, A2-OS interval is correlated to the diastasis duration, or, in other words, the time that the heart relaxes, without being filled by mitral valve opening. The opening of the valve is what marks the end of this phase.


Well, the more stenosed the valve is, the greater the atrium pressure. The greater the atrium pressure, the sooner the atrium pressure will be greater than ventricle pressure and the sooner the valve will open and you'll hear an Opening Snap.



Sorry for english again.
Reply With Quote Quick reply to this message
The above post was thanked by:
darbi (03-27-2016), drkanthiomc (10-31-2013), Mondoshawan (02-01-2011), shaan.medico (02-01-2011)
  #6  
Old 02-01-2011
USMLE Forums Addict
 
Steps History: 1 + CK
Posts: 109
Threads: 26
Thanked 32 Times in 14 Posts
Reputation: 42
Send a message via Skype™ to shaan.medico
Default thanx....

thanx for such a nice explanation, now i got it............
seems u hav pretty nice concepts.........
Reply With Quote Quick reply to this message
  #7  
Old 02-01-2011
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 590
Threads: 31
Thanked 1,233 Times in 411 Posts
Reputation: 1257
Default

Excellent explanations, thanks!

P.S. GGossling - your English is great; no need to apologize!
Reply With Quote Quick reply to this message
  #8  
Old 02-07-2017
USMLE Forums Newbie
 
Steps History: Not yet
Posts: 1
Threads: 0
Thanked 0 Times in 0 Posts
Reputation: 10
Default ?

the more stenosed the valve is--> the greater the atrium pressure

I don't fully understand why a stenosed valve would instantly lead to greater atrium P, unless a longstanding stenosed valve had already caused the LA to enlarge due to increased volumetric stress from the stenosed valve previously opening later, and thus this remodeling leads to an earlier opening precisely because of the greater pressure exerted by the increased volume.
Reply With Quote Quick reply to this message



Reply

Tags
Cardiovascular-, Physiology-

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Increased coronary blood flow in aortic stenosis ecgram USMLE Step 1 Forum 2 05-22-2010 01:16 PM
Mitral Valves silakan_isi USMLE Step 1 Forum 6 05-22-2010 09:20 AM
Aortic stenosis FSUSTC USMLE Step 2 CK Mnemonics 0 03-23-2010 06:41 AM
Murmur of Aortic Stenosis versus Hypertrophic Obstructive CardioMyopathy FSUSTC USMLE Step 2 CK Forum 2 03-04-2010 08:18 AM
Murmur of Mitral Regurgitation Xaquake USMLE Step 2 CK Forum 2 02-28-2010 10:11 AM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

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