Let us get into an important topic called
hypertrophic obstructive cardiomyopathy. First
we will walk through the pathophys and then
we will take a look at various maneuvers once
again in which you will clearly be able to
see as to how these maneuvers are going to
affect that particular pathology. In hypertrophic
obstructive, now there is hypertrophic cardiomyopathy,
in general, okay. That is a general type of
cardiomyopathy. HCM along with RCM, NDCM.
Theoe are all different types of cardiomyopathies.
The one that we will focus upon is hypertrophic
cardiomyopathy, specifically the obstructive
type. What does that even mean? This is the
one in which the outflow tract from the left
ventricle, going into the aorta. Do you see
the arch of aorta there in dark green? And
there is your left ventricle and that's a chamber
and it's the fact that you have blood? That is
then or should be ejected from your left ventricle
into the aorta, correct? Well, I want you to
pay attention to the intraventricular septum
and the outflow tract would be the exactly
as it would imply the outflow of blood from
your left ventricle into the aorta. And the
intraventricular septum that you are seeing
there and only exclusively on the left side,
you have asymmetrical hypertrophy of the left
side of the intraventricular septum. So lie
down there, listen to what I just said and
make sense of this picture. That intraventricular
septum that you are seeing there with the
aysmmetrical hypertrophy, moving into the chamber
of the left ventricle is causing obstruction
of the outflow. May I ask you a question?
Who is this patient? Inspiration, leaning back, ouch,
I have chest pain. But what then causes your
chest pain to be relieved? Hey doc, leaning
forward. Expiration, what does that mean to
you? Pericarditis. What do I bring this
up? Why was there increased pain upon leaning
back and inspiration? Inspiration increases
the amount of blood and with leaning back,
pericarditis is my diagnosis in which the
space between the pericardial cavity is then
going to cause friction and hence the pain.
Why do I bring that up? Because the two
layers here that you want to be able to keep
seperate so that the intensity of the murmur is
going to be decreased would be that outflow
tract. So if you are able to keep the left
sided asymmetrical hypertrophy, away from the
wall of the aortic valve, then guess what?
You are able to decrease the intensity of
the murmur. Who is this patient? Unfortunately
it is a patient in which we are seeing for
all intended purposes, perfectly normal. In fact, perhaps
even too normal in terms of
being maybe a star athelete. So there is nothing
in terms of obesity, in terms of maybe
lack of proper nutrition and such, that would
have contribute to the issue. Genetically
speaking, autosomal dominant, one of the major
contractile fiber is beta-myosin,
which is then affected in this patient,
resulting in asymmetrical hypertrophy
and obstruction of the outflow. And so therefore,
the closure that the outflow tract gets the
worse off is the intensity of the murmur and
the fact that the patient is going to have
such little cardiac output. Next time that
he or she goes for an exertional type of activity,
collapses onto the floor, never to get up ever
again. Sad. So your next question is what
kind of maneuvers are you going to perform
or are you going to see? What kind of drugs might
you want to give in which what do you want
to do here with obstruction? You want to relieve
the murmur by increasing space of the outflow
tract. How would you go by doing that? How
about increase the amount of blood in the outflow
tract? About increase the amount of preload
in your left ventricle so that you keep the
areas seperate and apart. And by doing so, would
you be able to alleviate the symptoms of the
patient and perhaps even save your patient?
Oh! My goodness yes and so, therefore, what
kind of drugs might you be thinking about?
What kind of drug might you want to give so
that you would be keeping more blood in your
heart please, a negative or positive inotropic
agent? A negative inotropic agent such as
a beta-blocker, such as a calcium-channel
blocker. By doing so, you then create negative
inotrophy, increased preload and seperation
of your outflow tract. Quite different isn't
it, when compared to aortic stenosis and such.
It is still systolic murmur. This is hypertrophic
obstructive. Where would you hear this? We've
talked about this earlier as well. Hypertrophic
obstructive. Take a look at the arch of the
aorta. Normally where would you hear the aortic
valve? Second intercostal space right parasternum
and then the outflow tract will be towards
the apex. It would be approximately third
intercostal in left parasternal. Is that
clear? So systolic murmur. Both aortic stenosis
and hypertrophic obstructive, but the locations
are different based on the anatomy that you
are seeing here. Let us continue.
Physical examination, a systolic ejection
murmur, heard where? Over the aortic area similar
to aortic stenosis, but the outflow tract,
so you could technically and will technically
hear on the left parasternal. Murmur, now
be careful, take your time. You want that seperation
of the outflow tract. Correct? Are you with me? If you want
the seperation of the outflow tract you want
less or more blood in your heart? You want
there to be more blood in your heart so you
have more seperation at the outflow tract.
When you do a Valsalva maneuver, phase II is
what? I assume you know that this is we're referring to,
then there is decreased venous
return to the left side. There is going to
be less blood in your heart. Pay attention.
One, there is less blood in your blood. Tell
me about the outflow tract. It is closer together.
What then happens to the intensity of the
murmur? It will worsen. What do you think
when you are standing up? Same concept.
Standing up, the blood is in your legs. Therefore,
you have decreased return to the heart, thus
worsening of HOCM, hypertrophic obstructive
cardiomyopathy. Versus, what if you squat quickly?
You increase your venous return, quickly squatting.
Remember this is not a tet spell. Rapid squatting
increases the amount of blood to your heart
and so, therefore, you are thinking about
your outflow tract, which is now more seperated.
What if you do a handgrip? If you do a handgrip,
what is interesting? It is that you will be
referring to what? More of an influence on
your afterload resulting in its increase thus
there is going to be more blood left where?
In your left ventricle. Is that clear? So,
therefore, what happens to seperation?
It is increased. What happens to intensity of
the murmur? It diminishes. If you have understood
all this, you are in great shape with HOCM.
Now as we progress, we are going to put all
the murmurs together with all the different
maneuvers. You probably want to keep coming
back to this lecture series so that you see
as to how well you have understood this material
and then it becomes part of your unconcsious
reflex. The physical examination,
double beat bifid
or spike and dome carotid pulse, hypertrophic
obstructive. It differs from aortic stenosis,
which has what is known as what? Slow and
delayed up in the carotid. Remember that is
called pulsus parvus et tardus. Delayed and
it is going to be slowed with aortic stenosis.
Whereas it is bifid kind of like a double beat when
you have hypertrophic obstructive. Not the