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