Pulmonary Hypertension Explained Clearly by MedCram.com

Pulmonary Hypertension Explained Clearly by MedCram.com


well welcome to another MedCram
lecture we’re going to talk about pulmonary hypertension this is an
interesting topic there’s been a lot of developments recently so let’s get
talking about pulmonary hypertension so you have to know the definition first of
pulmonary hypertension and there’s a couple of ways of measuring it the first
one is looking at the mean pulmonary artery pressure and the other one is
looking at the systolic this is how you measure it and but by definition it’s by
the mean pulmonary artery pressure and generally speaking if it is greater than
or equal to 25 millimeters of mercury at rest or greater than or equal to 30
millimeters of mercury at an exercise that will meet the criteria for you
having pulmonary hypertension systolic is used when we are trying to estimate
using echocardiogram we’ll talk about that echocardiogram okay so there are
major different categories for pulmonary hypertension let’s talk about those so
these are the five different whu-oh groups this is the World Health
Organization they’ve divided pulmonary hypertension into five different groups
so what are the different groups the first one is actually termed as
pulmonary arteriolar hypertension and the key there is this word arteriolar
because all the other ones are really just PAH or pH I should say pulmonary
hypertension and we’ll talk about those but PAH has to do with the artery so why
is the artery enlarged so this includes the term what it used to be known as
this primary pulmonary hypertension so I’ll just put primary pulmonary
hypertension but specifically it’s idiopathic pulmonary hypertension so
this was typically in young women and really couldn’t find a reason for
why the pulmonary artery pressures were enlarged but then it also included some
secondary forms of pulmonary hypertension that having to do with
collagen vascular diseases HIV portal hypertension even schistosomiasis
chronic hemolytic anemia persistent pulmonary hypertension of the newborn
even pulmonary vino occlusive disease or even pulmonary capillary Humanzee o
mitosis so those are some of the more uncommon ones I think the one that you
really need to focus in on is this idiopathic pulmonary hypertension okay
but the reason why I include all of these in here is because the medicines
that we’re going to talk about really are for Group one there is another one
that fits into Group four which will talk about the new one but generally
speaking the new medications and even the old medications that we have for
Palmeri hypertension really are for this type so if you’ve got a patient that’s
got pulmonary hypertension in one of these other categories with maybe the
exception of number four these medicines really haven’t been shown to be very
beneficial so things like idiopathic pulmonary hypertension there’s even one
now that we’re thinking about it here that has a gene called the bone
morphogenetic protein receptor type – okay so type 1 is a huge massive group
of different types of idiopathic pulmonary hypertension so let’s talk
about number two because these are all different – is pretty simple it has to
do with left heart failure okay number three has to do with lung disease okay
so that would include COPD that would include idiopathic pulmonary fibrosis we
can think of a whole bunch of other things even sleep diseases like
obstructive sleep apnea okay so things that causes hypoxemia
alveolar hypoventilation disorders like obesity hypoventilation things of that
nature group four has to do with pulmonary embolism and chronic VTE now
there’s a medication that we’ll talk about that actually is approved for
whu-oh four and then finally five was kind of left there for those that are
unclear so hematological disorders
myeloproliferative disorder splenectomy sarcoidosis is one glycogen storage
diseases fibrosis in medius tinnitus about chronic renal failure okay so what
I want you to take home from this is number one is PAH it has to do with the
artery it’s pulmonary arterial or hypertension and the biggest one that
fits into that category is the idiopathic pulmonary hypertension but
there’s also collagen vascular diseases etc number two left heart disease number
three lung disease number four pulmonary embolism number five sort of the grab
bag like sarcoidosis there’s also amphetamines which can also
fall into type one and so and feta means okay so we’ve divided these up into the
different categories let’s actually talk about now some of the physical diagnosis
findings how do you actually diagnose pH and then the treatment for pulmonary
hypertension in this and the next videos so let’s move on to some of the physical
findings okay let’s talk about the heart sounds the first thing that you’re going
to notice here is that there’s going to be a loud p2 and that’s because of the
pulmonary hypertension that is closing very hard the pulmonic valve the other
thing that you’re going to notice is a murmur of tricuspid regurgitation which
remember is hollow systolic you’re also going to have right ventricular heave
that you might feel on JDP because of the pulmonary hypertension
you’re going to notice larger c/v waves okay
otherwise known as regurgitant waves and it’s this regurgitation that allows you
to estimate the PA pressure the liver is going to be pulsatile the legs are going
to have edema and on chest x-ray what you’ll notice is something we call
pruning of the blood vessels so in the middle of the chest whereas normally you
would see these blood vessels go out what happens is because the pulmonary
hypertension is these blood vessels don’t go very far they stay in the
middle they’re enlarged and they stay in the middle and then for the most part
the periphery is generally free of blood vessels so it’s almost this all a gimme
ax or darker lung fields on the peripheral chest x-ray okay so what
would you think you might see on a EKG so on EKG what you would expect to see
is right ventricular deviation so an r v h maybe a right axis the other thing
that you would see is an enlarged right atrium so if you remember and lead to
you would have a peaked or a tenting P wave okay that would be what you would
expect also if you have right ventricular hypertrophy remember in lead
v1 you’re probably going to see a large V wave you might even see a right bundle
branch block depending on how much enlargement there is however the biggest
thing that you’re going to see is an echocardiogram and what what’s going on
here is if we were to look at the heart here’s the right side and here’s the
tricuspid valve if we get an echo machine an echo probe which is looking
exactly on that tricuspid valve every time that right ventricle
contracts it’s got to pump blood into the pulmonary outflow tract and to do
that it has to overcome the pressure to get the blood into
the pulmonary artery well when that happens the pressure here in the right
ventricle is going to be equal to the pressure in the pulmonary artery
well this tricuspid valve may not close completely and so what’s going to happen
is you’re going to get a tricuspid regurge attend jet going away from the
probe now if it’s going away at a zero degree angle then we can directly
measure the velocity of that regurgitant jet and that velocity is related
secondary to the modified Bernoulli’s equation to the pressure that’s in the
right atrium the fact that the right atrial pressure is lower means that
there’s going to be a regurge than jet the difference between them is going to
affect the velocity of that wave and the way it’s affected is that the change in
pressure is equal to four times the velocity squared so if we know what the
velocity is let’s say it’s three meters per second we can square that which will
give us nine and multiply it by four and in that case nine times four would be
thirty six millimeters of mercury so this becomes very helpful in estimating
this is an estimate of what the PA pressure is to this this is the
difference between the right atrium and the right ventricle so what you need to
do is add the pressure the absolute pressure that is in the right atrium so
you’ll know what the actual pressure is and the right ventricle so for this we
add the RA pressure now we estimate that by looking at the IVC if the IVC is very
distended then we give it a fifteen if it’s moderately distended we give it a
ten if it’s collapsible we give it a five and we simply add it to the four v
squared number so echocardiogram is very helpful so what is Ecco good at doing
number one it’s good at estimating the pulmonary artery systolic pressure not
the mean but the systolic pressure we talked about that before number two it
can also measure things like the right atrial size and the right ventricular
size to show how long this has been going on for because the pressures on
the right side are higher than that on the left the question then then becomes
is there a patent for amen Ovalle and to do that you’re
going to have to inject bubbles so you can do a bubble study and that’s very
helpful to see if there is a shunt process going on the other thing that
has to be done is when you want to confirm this is you want to do something
called a right heart catheter now right heart catheter is when you stick the
catheter down into the right atrium into the right ventricle and then out through
the pulmonary artery and you actually measure now what the pulmonary artery
pressure is so here you get an actual measurement of the PA pressure this is
not the systolic pressure we’re going to get the systolic we’re going to get the
diastolic and we’re going to get the mean and that’s where we can find out if
the patient actually has pulmonary hypertension so before we actually treat
anybody we really want to make sure we have a right heart cath the other thing
that a right heart cath allows us to do is to wedge the balloon catheter into a
pulmonary artery so we can figure out what the left atrial pressure is and if
the left atrial pressure is less than 18 that means it’s not due to left
ventricular failure and so that would rule out a group too and would rule in a
group one and the pressure that we’re looking for there is approximately
around 18 the mean artery pressure again what we kind of want that is to be above
25 millimeters at rest and 30 millimeters with exercise okay well join
us for our next video where we talk about the treatment of pulmonary
hypertension you