Mitral Valve Stenosis: Diagnosis, Treatment, Pathophysiology

Mitral Valve Stenosis: Diagnosis, Treatment, Pathophysiology

December 8, 2019 1 By Jose Scott


okay well two another MedCram lecture
we’re going to talk about mitral stenosis it’s like about the features
the symptoms the physical diagnosis the diagnosis treatment and when to do
surgery on mitral stenosis so almost all mitral stenosis is related
to rheumatic heart disease remember what rheumatic heart disease is you have an
infection and then you have these antibodies that are floating around that
would like to attack bacteria but instead they attack your valves and
specifically we’re talking about this mitral valve here typically this occurs
20 years after rheumatic heart disease and we usually see romatic heart disease
in there we’ll countries for some reason in the tropics it tends to occur more
quickly it’s sped up than it does in the more northern latitudes we’re not
exactly sure why that might be but think about this in 30 year old patients it
may be younger if you’re talking about in the more tropical areas of the world
you’re going to see this in the 30 year old patients because 20 years ago when
they were 10 they may have had a rheumatic heart disease or some sort of
a an infection at that time so the symptoms are pretty straightforward
basically you’re going to see dis Mia which is shortness of breath you’re
gonna see orthopnea which is shortness of breath when you lay down and you
might see something called paroxysmal nocturnal dyspnea where they basically
wake up and they’re all of a sudden short of breath sometimes you might
actually see hemoptysis this is because there’s so much back pressure in the
left atrium going back to the lungs that the small capillaries in the lungs
actually rupture and you get like pink frothy sputum type of thing so you might
actually see him opt assist with this but it’s it’s kind of rare II don’t
expect to see that because the left atrium gets so large you might also see
atrial fibrillation and that usually occurs because you’ve got a dilated
atria and because it’s so dilated sometimes you might even see thrombus in
there sometimes because this is sews the notion in the left ventricle that can
cause problems sometimes the left atrium can become so
large that it will actually splay the left mainstem bronchus up and cause
obstruction and you can get pneumonia so those are all different possibilities
that you can see in terms of symptoms for mitral stenosis but the big one that
you should know about it’s just shortness of breath shortness
of breath when lying flat shortness of breath when laying flat at night and
waking up short of breath going to the window type of thing I guess if you were
to have a thrombus here it got kicked off it would go out into the systemic
circulation and you could go up and get strokes so a CVA okay so in terms of
physical diagnosis you’re going to notice that the s-1 is going to be
louder and that’s because of the stenosis of the mitral valve remember
when the when you have systolic ejection of the left ventricle you’re going to
have ejection of blood it’s going to close this if it is relatively stenosis
it’s going to cause a louder s1 the other thing you’ll notice is remember
the opening snap the opening snap occurs at the beginning of diastole when the
the mitral valve opens the one thing I should say about the opening snap is
that it occurs right after s2 so you have this thing called s2 /os and
remember s2 marks the end of systole and the beginning of diastole the key here
is that if the opening snap occurs earlier and there used to be trained
physicians that could actually measure this into the hundreds of seconds but
suffice to say that if the opening snap is heard earlier that means it’s opening
up early in diastole and that could only mean if it’s opening up earlier that
there must be a bigger gradient across this valve the bigger the gradient the
worst the mitral stenosis so let me review that if you have bad mitral
stenosis the pressure in the left atrium is going to be much higher than that in
the left ventricle and diastole as a result of that the opening sound or the
opening snap is going to occur earlier so earlier equals worse now the murmur
itself is best heard at the apex you may even want to get the patient in the left
lateral decubitus position but what you’re going to hear is a low-pitched
rumbling diastolic murmur rumbling okay this is the same murmur
that you might want to call an Austin Flint if you’re seeing aortic
regurgitation so low-pitched diastolic rumbling murmur
what is going to make this larger anything that increases the amount of
blood on the left side of the heart is going to make this bigger so on
exhalation okay that’s gonna do it so an exhalation you have a shift of a
septum going to the left the right side becomes bigger the left side becomes
smaller so exhalation is gonna make the sound larger things that will make the
sound smaller would be a valsalva because remember a bell selva makes the
heart small on both sides this is the murmur now what else might you hear you
might hear a p2 now what might you hear a p2 because if the pressure in here is
built up it’s gonna back up through the lungs into the pulmonary artery which is
going to make a larger sound than you would normally have so you’re gonna have
it increased p2 and as a result of that you may also see if it’s been there for
a while right ventricular hypertrophy because you’ll have elevated pulmonary
artery pressures so I think the keys here are that you’re gonna see it
increase s1 you’re gonna hear an opening snap the earlier the opening snap the
more severe the mitral stenosis you’re gonna hear a low pitch rumbling
diastolic murmur and you may hear a p2 due to pulmonary hypertension and
increased right ventricular lift from right ventricular hypertrophy okay let’s
talk about diagnosis on EKGs what you’ll see is enlargement of the RV and the
left atrium and you might see atrial fibrillation so what do you see with an
RV if you look at the precordial leads like v1 v2 v3 you’re going to see that
the QRS complexes are going to be large okay so those think about right
ventricular hypertrophy the QRS complexes are going to be large in the
precordial leads in terms of left atrium also look at v1 v2 and what you’ll
notice there is you’ll see that there’s a large up component and
then down component before the QRS if it’s more than one small box up and one
small box down in terms of this measurement here on the p-wave that
shows that there is a large left atrial size or of course you could have atrial
fibrillation where there won’t be any P waves at all and that could be a sign
that you’ve got mitral stenosis not very specific but definitely something to
pick up on what about chest x-ray well if you have your chest x-ray you’ll
notice on the chest x-ray that sometimes you’ll have this double bubble so you’ll
have the heartburn border and then behind it right about here you’ll see
another double density that double density is actually the left atrium I
encourage you to go online and take a look at some x-rays of people with
mitral stenosis so you can see it it’s almost pathognomonic and you might see
it on a test the other thing you might see if the mitral stenosis is fair
enough is you’ll see what we call cephalization so the pulmonary
vasculature is going to be engorged or you might see flat-out pulmonary edema
but the real key to diagnosis is echocardiogram once again and with
echocardiography you’re going to see a large left atrium and you’re gonna see a
mitral valve that does not allow flow to go through and there’ll be a huge
gradient here and that’ll tell you that the Doppler on that echo will tell you
the severity of the stenosis is kind of a way of actually visualizing the
pressure gradient and see the thing that leads to the early opening snap of
course if that is the case the next step is cath because in this situation you
can do surgery or treatment for this so we’ll talk about that now because the
lungs are filling up with fluid and the patients are usually dis neck
we usually use loop diuretics like lasix the other thing to do is if you’ve got a
trio fibrillation need to treat that and so anticoagulants like coumadin and rate
control you want to keep the rate down unlike in a auric insufficiency and
certainly if there are clots here you don’t want those clots to go through and
embolize up to the brain so anticoagulation will be key now
sometimes you can actually do balloon valvuloplasty that’s react
go onto balloon and open this area up that’s usually effective if there’s no
calcification of the valve where things could break off and go and embolize or
there’s regurgitation if there is regurgitation in addition to stenosis
then you want to go with valve replacement so you can do balloon
valvuloplasty or you can just do what we call a mitral valve replacement and
remember this is even more clot provoking than the aortic valve and the
reason is is because across the aortic valve you have very high flow the mitral
valve on the other hand is much bigger and therefore there’s not as fast flow
it’s very slow flow and so this is a very clot forming it’s very high risk
for clot form and so you need anticoagulation if you do a mitral valve
replacement especially if it’s mechanical sometimes they’ll say even
the INR must be between 2.5 to 3.5 and of course if they stop anticoagulation
they have to be bridged which can get a little dicey sometimes in terms of
surgery so that sums up mitral valve stenosis the feature symptoms
pathophysiology diagnosis and treatment thanks for joining us you