What is cardiomyopathy? | Circulatory System and Disease | NCLEX-RN | Khan Academy

What is cardiomyopathy? | Circulatory System and Disease | NCLEX-RN | Khan Academy

– [Voiceover] In this video,
we’re going to be talking about what is cardiomyopathy? And to start, I just want to write cardiomyopathy in three parts. And the reason I do this is
because if you break down cardiomyopathy into these three parts, you get an understanding
of what the disease is. Because cardio stands for
heart, myo stands for muscle, and pathy stands pathology or disease. So you can get an idea that cardiomyopathy is a disease of the heart muscle. Alright now, before we really
dive into cardiomyopathy, let me just kind of go
over, do a brief review of what the heart muscle exactly does. So I like to think of the
heart as a series of two pumps that are separated by the lungs. So let’s draw that in here. And this first pump I’m going
to call the right heart. And the second pump I’m
going to call the left heart. So the purpose of the right
heart is to bring blood from the body and send it to the lungs. So let’s see how that works. Well, think about this pump
just kind of drawing up here, and it’s going to bring in some blood, so let’s see that happen. So now that the right
heart has drawn blood into it from the body, it’s now going to pump
that blood to the lungs. Then once in the lungs,
the blood is oxygenated, and then the left heart
is used to pump the blood from the lungs to the body. And this is in a very similar
manner as the right heart. So let’s see that here. And what’s cool about the heart is that these two pumps are
actually pumping simultaneously. They’re both going up and
down, and bringing blood from the body to the lungs and
from the lungs to the body. And then this blood actually
that’s going to the body eventually circulates
back to the right heart. It goes to all the different
organs where oxygen and different nutrients
and waste are changed before it goes back to the right heart. And it just circulates like this. And it’s these two pumps that keep the blood moving through the body. So this is just kind of a very simplified diagram of how the heart works. Let’s put in a little bit
more anatomical diagram of the heart to give you an
idea of how these two pumps are kind of contained in
one unit that is the heart. So here we have a diagram of the heart. And I want you to think of
this heart as if you’re looking at someone and this
heart is inside of them, so it’s kind of mirror-imaged. So over here on the left
we have the right heart. And then over here on the
right, we have the left heart. Now what happens in the
heart is that this muscle, the walls of the heart are a big muscle. And when these muscles relax, the chambers of the heart
actually get bigger. So let’s kind of see that. And this dilation of the chambers, just like in the pumps up here, it draws blood into the chambers. And this is where I say
it’s kind of like two pumps, because it’s at the same
time it’s drawing blood in up in the right heart from the body, and at the same time, it’s
also drawing the blood into the left heart from the lungs. Now that the blood is into this chamber, into these two pumps, the heart muscle, this wall here, it contracts, and it makes that chamber a lot smaller. And it’s this contraction
force of the muscles that actually expels the
blood in the heart chambers to either the lungs from the right heart, or to the body from the left heart. So now that we have an
idea of how the heart works as two separate muscles within one unit, pumping blood from the body to the lungs, and from the lungs back to the body, I’m going to kind of erase
my work here and show you how the heart muscle
itself can become diseased and result in a cardiomyopathy. Alright, so I’m just going to
draw three more pumps here. So there’s kind of three ways that the muscle of the heart can fail. And the first one is that
you can have a power failure, or you can have a pump
that’s just too small. And lastly, you can have a blockage. So in this first example,
the pump is supposed to kind of go all the
way up and down here. But imagine if this pump
doesn’t have quite enough power, and it’s not able to
pump this full distance. Say it’s only able to pump
maybe from like here to here. Just this very short distance. So every time this pump goes up and down, it’s still working in the fact that since that it’s drawing blood in from
the body or from the lungs. But it’s just not drawing
as much in with each pump, and therefore when it pumps out, it’s also not pumping as much out, so this pump is not as efficient. And it’s failing, and so I’m
going to just define failing here as kind of a decreased
output of the pump. So if your pump’s only going
a little bit up and down, if you have a power failure, you’re going to have a
decreased output of the pump. And another problem you
could have with your pump is that the chamber of
this pump is too small. Now this pump, it has a
smaller chamber in the side. So, even if this pump is able to pump that full distance up and down, it’s still not bringing as much volume, as much blood into the
chamber and pumping it out. So in this case, you
have this power failure where it’s not going up and down as much, so the output of the pump is lower. In this case it’s going
up and down all the way, but the chamber’s smaller,
so the volume of blood it brings in and out is also decreased. So maybe I’ll write that in here. We have a decreased flow
coming out of the pump, and over here we also have a decreased flow coming out of the pump. Alright, so how about this last mechanism. Well, let’s just imagine
there’s a blockage here kind of in the outflow of this pump. And so now when this pump is going, even though it’s going the
full distance up and down like in this example,
but the flow of the blood that’s trying to come out of
the pump it’s getting blocked. And so you’re not getting as
much flow out of the pump. So that once again here, we’re going to have a decreased flow. And these are the three
different mechanisms by which the heart muscle can fail to result in a cardiomyopathy. So let’s see how that
works with a few hearts. Now let me just draw these hearts in here. Alright, so in this first example, I said we have a power failure. Well, what does that look
like in cardiomyopathy terms, and what happens in the heart? Well, what happens when
you have a power failure is actually the chambers
of the heart dilate a lot. So let’s draw that in
here, they get really big. So when the chambers of
the heart dilate like this, it actually stretches
the muscle really thin of the heart wall, and that muscle that’d been stretched so thin, it’s not as affective at pumping. It doesn’t have as much power,
so kind of like up here, where it can kind of just go
up and down just a little bit, but not the full pump. That’s kind of what happens here, is that the heart muscle
isn’t able to fully pump. And so even though it’s getting bigger, it’s still kind of got this power failure. It’s not pushing as much
blood out of the two pumps. And this power failure and
dilation of the heart chambers is known as Dilated Cardiomyopathy. And so Dilated Cardiomyopathy
is kind of aptly named because the heart chambers become dilated, and it’s that dilation
that thins the muscles that causes it to have
a decreased forward flow and a failure of the heart. So now let’s talk about
this small pump example. And how does this correlate
to a cardiomyopathy? Well, in this case, the muscle walls of the heart chambers become really thick. So I’m just going to draw that in here. And when this happens, when these walls become kind of thick and scarred down, they’re not able to expand. And that expansion, or
relaxation of these muscles, is what draws blood into the chambers from the body or from the lungs. And so it’s kind of like here, where you have this smaller chamber now that it can’t dilate out, the chamber effectively becomes smaller. So even though every
time this muscle flexes and it pumps the blood out,
it’s pumping almost all of the blood that’s
contained in these ventricles or these chambers, but it’s not able to bring enough in to actually
have a normal flow out. And this is known as
Restrictive Cardiomyopathy. So now let’s go to this last example here, where we had a blockage of the outflow. And how does this relate
to a cardiomyopathy? Well, in this example, there’s also kind of this
thickening of the heart muscle. However, in this case, this thickening of the muscle
wall is actually asymmetric. And in this center portion
here, known as the septum, it becomes really hypertrophied,
it grows really big. And it actually blocks the outflow of blood through the aorta,
which is sending blood from the left heart here to the body. And so you get this
blockage, but you also do kind of have some of this
small pump phenomena. And this is known as
Hypertrophic Cardiomyopathy. So to recap this real quick. Just remember that if
you break down the name, you can kind of remember
that cardiomyopathy is a disease of the heart muscle. And this disease of the
heart muscle results in a decreased outflow
of blood from the heart. And it can kind of be caused
by three different mechanisms. You can either have a pump failure, as you see in Dilated Cardiomyopathy. You can have a pump that’s just too small, like as in Retrictive Cardiomyopathy. Or you can have this blockage of the outflow of the
blood from the heart, as you have seen in
Hypertrophic Cardiomyopathy.

35 Replies to “What is cardiomyopathy? | Circulatory System and Disease | NCLEX-RN | Khan Academy”

  1. That's a very cool! Are you using some kind of apps that can do animation now? Previously it was all about erase, draw, erase draw but that heart pump animation is really neat

  2. oh there's 2 YouTubers I watch one's a gamer and the other is a gamer and a vlogger Zach Steve Peters from TheZachMan18 and Caleb Logan LeBlanc from Bratayley and Blazenoutlaws before he died his channel was changed to FlimsyArrow and it's now a TruthPlusDare channel so it's called The Arrow Faction now Caleb and Zach had died from the 3rd one Hypertrophic Cardiomyopathy Caleb died at the age of 13 on October 1st 2015 and Zach died at the age of 16 on March 25 2015 he was 3 years older than Caleb R.I.P Zach and Caleb

  3. Hey! I'm sky diving in aid of Cardiomyopathy UK charity, if anyone would like to help us out by donating it would be so amazing!
    If you can't donate you're welcome to help by sharing my link!

  4. This is a good explanation, my doctors answer any questions I have, but this is easier to understand what l have. Thank you 🙏

  5. super awesome, but can you guys make one for Fetal Cardiomyopathy in how it affects the velocities due to the fetal shunts and the circulatory system. Please 🙂

  6. Thanks very informative and easy to understand and i must say this is one of the excellent lecture every come across.

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