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

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


– [Voiceover] So your heart pumps blood essentially to two places and the first place is your body. So you have your oxygenated
blood on the left side and we gotta remember that the lefts and the rights are switched because we’re looking at the
anatomical view of the heart. So it pumps it out to your body and your body gets that oxygen. Your body uses it up
and then circulates it back into the right side where this time it’s
pumped out to the lungs and gets re-oxygenated
and gets that oxygen back and then it’s circulated
back into the left side. And the amount of blood at any time pumped to your body is sort
of based on this demand that your body has for blood. You can kind of think of
it like you have this gage that says, “Hey, I need this much blood “to sustain this much activity.” And this can change, so if you start working out or something, your demands might go up and your heart can accommodate for that and start pumping more blood to that body to meet those new demands. Heart failure describes this condition where the heart can’t meet
the demands of the body. So at any given time, the heart’s not able to pump enough blood to
meet the body’s demands. And there are essentially
two types of heart failure. The first one we call
systolic heart failure and systolic refers to systoli, which is the phase of the cardiac cycle where blood is pumped out of the heart and so systolic heart failure is when those heart muscles
aren’t pumping blood with enough force. So this often means that
those muscles are weakened and smaller than with a healthy heart and this typically makes it
look quite a bit different. And when these smaller muscles contract, they don’t squeeze as hard as they used to and this causes less blood to be ejected with each contraction. Now, I say contraction because the heart’s this muscle, right? So, when it contracts, it squeezes. You can kind of think of it like you have this water bottle that
you’re holding with your hand and you squeeze the water bottle and it shoots the water out. It’s the same concept with your heart. When those muscles contract, they squeeze the blood and that’s how you eject blood to both
your body and your lungs. With systolic heart failure, since your heart muscles are smaller, think about squeezing
that water bottle again, but just pinching it. It’s gonna be a lot harder to
squeeze the water out, right? Well, it’s the same thing for the heart with smaller and weaker muscles. It’s gonna be way harder for it to squeeze and pump that blood out to the body. You probably noticed that this heart has these sort of enlarged
looking lower chambers and at the same time, it has
this really thin muscle wall and these are really characteristic traits of a heart with systolic failure. And these small muscles
make it really hard for it to pump blood to the body. So that was the first
type of heart failure. The second type is called
diastolic heart failure and instead of being a pumping problem with the muscles being too small, diastolic failure is a filling problem which is why we call it diastolic failure, because it refers to diastoli which is that phase in the cardiac cycle where the heart fills with blood. So with this type of failure, your body’s not receiving enough blood because your heart’s not
filling with enough blood to pump out in the first place. So if we jump back to
that water bottle analogy, this time you’re holding it with one hand, just like we were for the healthy heart, but instead the bottle’s
filled with less water, so even if you squeeze
it with the same force as a healthy heart, less
water is gonna be ejected simply because there’s
less water in the bottle. And this is essentially what’s happening with diastolic failure. Since there’s less blood
filling in the ventricles, even if it’s pumping with the same force, less blood’s gonna be ejected to the body. But why is there less blood
filling in the chambers? Well, it’s because those muscles are actually larger in this case and they take up more space and this leaves less space for that blood to fill in to the ventricles. Okay, so far we’ve shown
both types of heart failure and each time we’ve shown
it happening on both sides. Well, this isn’t always the case. It’s definitely possible to
have isolated heart failure. So maybe you only have the left side or maybe you might only have
it isolated to the right side. One important thing to not though is that usually a left-sided
case happens first and then that ends up leading
to a right side failure. I know I’m only showing
systolic failure here, but I should not that
this isolated failure can happen with either
systolic or diastolic. So, depending on which
side this is happening on, the left or the right, the symptoms are gonna
be a little different. Let’s just go ahead and start
with the left side first. So since the left side
pumps blood out to the body, that means it’s coming in from the lungs and if it’s not pumping it
very efficiently to the body, that blood starts to get
backed up into the lungs. Think of it like a traffic jam. What happens when they close a lane and then they only let
one car through at a time? All those other cars get backed up. It’s kind of the same thing. This blood gets backed up into the lungs because it’s only pumping a
little bit out at a time now. So a really common symptom
of left-sided heart failure is fluid build up in the lungs. This is called congestion and it’s also sometimes why we
say congestive heart failure. Alright, so that was left-sided failure. Let’s take a look at right-sided failure. Again, I’m just gonna
show systolic failure, but let’s just note that
this can either happen with systolic or diastolic. This time, since we
know that the right side pumps blood to your lungs, we also know that it comes from the body. And since it doesn’t pump
blood as well to the lungs, we have that traffic jam situation again, but this time it gets
backed up into the body. So patients with right-sided
failure might start getting fluid build up in
their feet, legs and abdomen. And again, just like the left side, you have congestion or fluid build up, but this time it’s in your
body instead of your lungs. So as a quick recap, you could
just have systolic failure on the right side or you could just have systolic failure on the left side and it’s possible to have both. In the same way, you can have diastolic on the right side only or you could have it
only on the left side. Or you might have both. It’s even possible to have a combination of systolic and diastolic failure. So now that we’ve kind
of nailed those down, let’s talk about this really important way that we measure the heart’s ability to meet the demands of the body and that’s called cardiac output. Cardiac output represents
the total amount of blood that the heart’s able
to pump every minute, usually given in liters
of blood per minute. And the normal cardiac output is around five liters per minute. Now, cardiac output can be broken down into two other components and the first is stroke volume which is the amount of
blood pumped out every beat which is different than cardiac output because it’s every beat, not every minute and so we take this stroke volume and we multiply it by your heart rate, which is measured in beats per minute and those two multiplied together equals your cardiac output. So if you were to change either
stroke volume or heart rate, for example, let’s say
I lowered stroke volume, since cardiac output’s dependent
on these two variables, cardiac output’s also gonna go down and that’s what happens
with heart failure. Cardiac output is lower
because the heart’s not pumping as much blood per minute. This is usually because
there’s a lowered stroke volume or a lowered amount of blood pumped out with each contraction. So usually heart failure is
considered a secondary disease, meaning that it’s caused by
some kind of pre-existing or underlying disease that
already affects cardiac output. Specifically, we’re gonna
think about diseases that cause the death
of cardiac muscle cells which are also called cardiomyoctes. And when those muscle cells die, the heart gets weaker and gets
way worse at pumping blood. This lowers stroke volume and then it also lowers
your cardiac output. And when the cardiac output goes down, the heart has two options
to increase it again. Based on our equation, that’s
stroke volume and heart rate. And your heart actually does that and this is called compensation. So your heart compensates
by either squeezing harder and increasing stroke volume, or beating faster and
increasing heart rate. In the early stages of heart failure these methods can
actually help quite a bit in compensating for decreased supply, but over time those surviving muscle cells become overworked because
they’re constantly trying to either beat faster or squeeze harder. But to do either of those things, those cells need more oxygen. This is the whole issue with heart failure in the first place, a
decreased supply of oxygen, those muscle cells
won’t receive the oxygen and more muscle cells tend to die off. And when more die off, stroke
volume goes down even more and this causes this whole cycle to repeat which causes heart failure to get worse.

Comments

(44 Comments)

  • Bis Tek

    Thank you so much for posting this video

  • kaylee bridgeman

    You made heart failure so simple to understand. Love the water bottle analogy. When I take my test tuesday i am going to picture the heart as a waterbottle lol

  • ScorpioQueen

    My dad past away from Hear failure. He had an Lvad for 18 months, the medicines and fluidpills caused him kidney failure. Im in so much pain 🙁

  • Narae Lee

    Your voice sounds familiar… Are you the same guys with Osmosis channel?

  • 金子皓

    嗷嗷

  • J

    Amazing

  • natalia holliman

    heart

  • Trevor Kemp

    Video abruptly cuts off at the end. Not picked back up on 2nd video in the playlist. Please fix. Otherwise, really great!

  • Luke Waddison

    I watch so many of your videos on all kinds of biology. Thank you so much, it really helps with my University studies with your brilliantly explained videos.

  • Mado Sh

    thank u very much

  • C.D.

    Thank you!! Maraming salamat po. 🙂

  • Saad Saeed

    Great

  • AAA

    are u the guy in Osmosis video?!

  • Banana Cupcake

    Hey it's the osmosis guy

  • Areeba khan

    nice

  • The Retired Poppy

    https://www.facebook.com/tamduffy/posts/10155531411722512

  • Sheila E

    Dr.Just clarify i have heat failure…Not easy living with…This💕 what i have…gored!

  • sara abdo

    It is the voice of who speaks in
    @osmosis

  • Sheila E

    I understand my condition better!

  • MuusiK Fan

    Is left ventricular dysfunction defined as left sided heart failure? What about both systolic and diastolic failure Grade 1? Is the Grading of heart failure based on the echo? Is not just a heart impairment? Is diastolic failure Grade 1 normal as we age? And is an enlarged heart "heart failure" or "cardiomyopathy??? Whats the difference between Heart failure and Congestive Heart failure? What if the patient suffers from both systolic and diastolic impairment, but EF is low normal, for around ten years, but suffers breathlessness, lightheadedness upon minimal physical task such as cleaning a mirror? Very confusing when reading the definitions. Aome HF patients are normal active others not so active and limited even if EF is normal, why is that? Thank you.

  • abbas thamer

    http://vializer.com/7PeN
    heart failure

  • srideviaful

    God bless you may you enger paradise with this good deed😭👍❤️🌹💕

  • ahmed shady

    👌👌

  • Shaheer Alvi

    Wao…u make it so easy for understandings…..tysm sir

  • Whatsup Status

    I like your video. Great information. Keep up good work. http://freee-study.blogspot.com/2017/07/about-congestive-cardiac-failure.html

  • Lisa Middleton

    I'm 41 & was diagnosed with Moderate Heart Failure August 2017…. https://youtu.be/dT_sNB_01gc

  • iuiukk9509

    simply superb.

  • AHMED Ali

    thank you so much its really help

  • Tom Vanheusden

    This is brilliant!

  • John Walters

    My wife passed away on 11th may 3 weeks ago only 35 her heart failed she had cancer 9yrs ago got over that but the chemo weakened her heart she spent month in hos fighting it but they found to many blood clots so wernt safe to operate. So after 2 weeks she rapidly went down hill and we had to turn machine of that was helping the heart as both sides failed in the end so she wernt getting the oxygen funeral on monday dreading monday

  • Rada Ny

    GGood but small letter

  • Fh Gf

    U sound exactly like the one from osmosis. Thanku for such good explanation

  • Jane Doe

    Thank you just so clear🙏🙏🙏🙏

  • Kittycat Forever

    I think i have it when was younger i was often in an hospital and i think heard my mom and the doctors saying something about it and my heart rate was 90-120

  • Moses m

    osmosis? is that you? loved the video

  • Khalid Almutairi

    I know this sound 🙂 (OSMOSIS)

  • Enwelum Precious

    Thank you

  • Sam Ahf

    Excellent lecture, any book you recommend or what books you are using for your lecture? Thank you!

  • ramicollo

    Is there any solutions to heart failure or methods to grow new heart muscles

  • Nicole Malmberg

    This was a very helpful video! Thank you!

  • Merve Kucuk

    Türkçe altyazı da koyar mısınız

  • H1N1

    Meds? Nursing considerations? Teaching? Hardly NCLEX. More like a brief overview.

  • Damian Pavlovski

    Awesome presentation. Thanks. I’m just wandering if you could tell me what is the software you were using?

  • Bonecrusher27WTF

    Very clear explanation. What I needed for a quick revision. Thanks!

  • Briana G.

    Awesome, amazing video but it cut off at the end 😕

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