[shaan.medico]

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................

 

[khanar]

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

 

[GGossling]

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.

 

[shaan.medico]

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???? :toosad:


OR i can say the other way round that, how a more stenosed valve opens earlier than a less stenosed valve?????

 

[GGossling]

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.

 

[shaan.medico]

thanx....

thanx for such a nice explanation, now i got it............
seems u hav pretty nice concepts......... :happy:

 

[Mondoshawan]

Excellent explanations, thanks!

P.S. GGossling - your English is great; no need to apologize!:happy:

 

[Penny17]

?

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.

 

[kiratd]

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.

Yeah, thats sounds reasonable.
As the disease progresses, LA pressures increase (as its not fully emptied due to stenotic valve), and so the point at which mitral valve open(OS) gets close to S2 gradually, indicating severity.