okay well to another MedCram lecture we're going to talk about mitral
stenosis we're talking 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 twenty 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 gonna see this in the 30 year old patients because 20 years ago when they
were 10 they may have had rheumatic heart disease or some sort of a and
infection at that time so the symptoms are pretty straightforward basically
you're gonna 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 they 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 so stano's you might actually get a jet
lesion 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 s1 is going to be louder and that's because of the stenosis of
the mitral valve remember when the when you have systolic
section of the left ventricle you're gonna have objection of blood it's gonna
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 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 in 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 going to 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'll make the sound smaller would be a valsalva because
remember of L Selvam it's 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 awhile right ventricular hypertrophy
because you'll have elevated pulmonary artery pressures so I think the keys
here are that you're gonna see an increase s1 you're gonna hear an opening
snap the earlier the opening staff 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 by 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 gonna 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 pea
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 for this
so we'll talk about that now because the lungs are filling up with fluid and the
patients are usually distich 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 arrogance efficiency 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 reaction to the 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 in 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 as fast
flow it's very slow flow and so this is a very clot clot forming it's very high
risk for clot forming 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 features symptoms
pathophysiology diagnosis and treatment thanks for joining us
you