Now, this is what I was referring to earlier,
with the WHO classification of Pulmonary Hypertension.
I am going to give you a brief description
for every single class that you absolutely
must know because the way that you approach
this or clinical vignettes, I will show you,
will be a class by class.
Begin with Class I. Now, we
will begin, chronological order, by
Class I. Clinically however, you will begin
this a little bit different. Why? Keep it
in mind. If it is familial, very difficult
to sometime figure this out immediately, isn't
it? So, it is easier to actually perform certain
tests that are a lot faster to rule things
out, Class II, III and IV, so then you would
highly suspect Class I. Let’s put it that
way. Once more, this is
familial. What does that
mean to you? Once upon a time, known as your
primary Pulmonary Hypertension, get away from
that, idiopathic pulmonary arterial hypertension
is a much better descriptive name. Majority
of these will be familial. Okay. That means
that there is no secondary effect. There is
no hypoxia in which there is there's pulmonary vasoconstriction.
There is no heart disease causing pulmonary
arterial hypertension and there is no thromboembolic
episode, chronically, resulting in increased
pulmonary hypertension. Right? This is familial.
So, it is actually faster and more effective
to rule out, and we will go through each one,
I,II,III and IV, and then to see as to whether
or not Type 1, in fact, is your proper
diagnosis. Now, what do you want to
know about familial? Oh, it's an inactivation
mutation of a particular gene called your
bone morphogenic protein-receptor-2. Know
the entire name. I'm sorry, you must. The
abbreviation is BMPR2. R is Receptor. BMP
is bone morphogenic protein. What does it
do? It normally inhibits the vascular smooth
muscle proliferation and so, therefore if
you have such a mutation, where you inactivate
the gene, which normally controls the proliferation,
where am I? Blood vessel. And so therefore,
if you remove this suppressor, you have increased
proliferation, end up having pulmonary arterial
hypertension. Prognosis, poor.
Okay, now, important causes include drugs
such as amphetamines, cocaine, connective
tissue disorders, HIV, portal hypertension
and congenital heart disease and schistosomiasis.
If I were you, I would take a look at each
one of these differentials. How do you rule them
out? Your patient is an addict. Your patient
has scleroderma. Do you remember a topic when
we had scleroderma and it was the continuum
of fibrosis that you are paying attention
to and it’s a fact that we had crust and
we had systemic type and so, therefore, if
it is fibrosis that you are dealing with,
then it is the fact that you are, at first,
having non-specific changes and then your
usual interstitial pneumonitis which we as
pathologist, are then going to describe it
as. Are we clear? Okay.
HIV, immuno-compromised. How do you rule out
something that’s causing liver injury? Check
out your liver function test. Are we clear?
That’s important. Rule things out.
Congenital heart disease. What kind of a test
might you want to perform on a patient to
rule out congenital heart disease? Good. A
Cardiac MRI or a Cardiac Magnetic Resonance
test. Clear? Schistosomiasis.
Well, that might be history.
Maybe patient came from North Africa, Egypt
specifically. That type of region where the
patient might have been exposed
to Schistosoma. That’s Class I.
Move on to Class II, please. Now Class
II, the way that I have thought about this
and the way that maybe might help you, Class
II, is there any way that you could
possibly think of your heart having two sides?
Would that perhaps help you? Okay. The
reason I say that is, Type 2, or Class II,
excuse me, type of Pulmonary Hypertension
is going to be trouble in your pulmonary blood
vessels secondary to the heart, secondary
to the heart. Are we clear? So, pay attention
to that and so, if it helps you to think of
the heart as having two sides. And
let’s say that you have right
ventricle hypertrophy and you have to start
on the left side. So, if you have left-sided
heart failure, then you might back up into
pulmonary veins. Right? You further back
up into pulmonary capillary, pulmonary artery.
So, therefore, here, the Pulmonary Hypertension
was due to a left ventricle heart disease.
That’s Class II. How would you rule this
out? Maybe something as simple as E & E. What
are these? Echocardiogram, EKG. Alrighty?