Heart Failure Explained Clearly – Congestive Heart Failure (CHF)

Heart Failure Explained Clearly – Congestive Heart Failure (CHF)


well welcome to another MedCram
lecture we’re going to talk about heart failure today now sometimes this can be
a little confusing because there’s a lot of different definitions this was known
as congestive heart failure and there’s been some new definitions that have been
introduced that have been a little bit confusing as well and we’re going to go
over the basics first here in the first lecture and tell you a little bit about
the definitions and also the path of physiology behind heart failure now
generally speaking if you look at the heart and we will symbolize that here
with actual heart remember the heart is just a pump and you’ve got blood going
into it and by definition all blood that goes to the heart must go to the heart
via veins and then you have blood coming out of the heart and by definition those
are arteries now of course in the pulmonic circulation the arteries have
deoxygenated blood and the vein has oxygenated blood and in the systemic
circulation all of the arteries have oxygenated blood and all of the veins
have deoxygenated blood and we’ll talk about that a little bit later but as you
can see the heart is meant to pump blood and have it flowing in the correct
direction generally speaking if you have heart failure you’re not going to get as
much blood going forward and you’re not going to get as much blood going in and
so as a result the two major types of symptoms that you’re going to see in
heart failure is not enough forward flow and because there’s not enough forward
flow blood stays in the heart and as a result of that blood which should be
entering the heart is not entering the heart and as a result of that you’re
going to see congestion before it okay this is like an accident on the freeway
there is no traffic in front of the accident because there’s not enough
forward flow but we certainly know there’s plenty of traffic before the
accident and there is quite a bit of congestion now things would be pretty
simple in this situation if this is all that we had and so we’re gonna get into
a little bit more detail but let’s look at how these symptoms manifest
themselves not enough forward flow could mean number one kidney function
decreases just think about all of the organs which are all of them that rely
on blood perfusion and if the kidneys are not getting enough blood you’re
going to have kidney function decreasing that of course is going to activate the
reno angiotensin system or the Rass system it will also activate the anti
diuretic hormone system of course this is going to increase the amount of fluid
retention that you have and that could exacerbate your congestive heart failure
number two think about your pulmonary system and think of chain Stokes
respirations okay so not enough carbon dioxide is circulating and therefore you
get chained Stokes ventilation where you breathe fast and then you breathe slow a
lot of the symptoms that you see are on the congestion side and so certainly
when you have congestion the first organ that it goes to is the lung so think of
pulmonary edema but if it keeps backing up you know that the next organ it’s
going to go to is the liver so liver congestion so you could see the ast and
alt go up this is also known as nut Meg liver because if you do a
cross-sectional of the liver it would look like there is nutmeg you would also
get elevated pulmonary artery pressures and also think of pedal edema so these constellation of symptoms can
be divided in problems associated with poor output and problems associated with
poor input or congestion and in any heart failure you could see both of
these types of symptoms now I want to talk about the heart itself now the
heart we set as a pump but it’s not your typical swimming pool pump which you
just turn on and just runs continuously it actually has two very distinct
actions it has an action of active contraction and it also has an action of
active relaxation and it’s this active relaxation that is the most
misunderstood and so there are two phases of this pump if you will a two
stroke pump where there is one phase called systole and there is another
phase called diastole now systole is where there is active contraction diastole is when there is active
relaxation if you have a problem with either of these two functions you could
get congestive heart failure systole is when the heart is pumping blood actively
into the aorta and to the systemic circulation and pulmonic circulation
when it relaxes however blood enters from the veins into the heart both the
pulmonic vein and also the inferior vena cava and allows the heart to fill if the
heart can’t contract you have something called systolic dysfunction if the heart
can’t relax you have something called diastolic dysfunction there is something
that is known as the ejection fraction otherwise known as the e F the ejection
action is simply the size of the heart @n diastole in other words the size of
the heart when it’s the largest – the size of the heart at and systole in
other words the size of the heart after it contracts so in other words what
we’re looking at here is how much blood was pumped out of the heart and we
divide it by the size of the heart at the end of diastole so what we’re saying
here is that the ejection fraction is the proportion of blood that the heart
can pump out in one contraction the thing I want you to notice is that if
the heart has a hard time contracting this number up here is going to get
smaller but this number is going to stay the same let’s review that again if
there’s a problem with systole if the heart is too weak to contract then these
numbers are going to be very similar and therefore the difference between them is
going to be very low this number will not change however
and so the ejection fraction will go down in systolic dysfunction
however in diastolic dysfunction remember what the problem is the problem
is is that the heart can’t relax and as a result of the heart not being able to
relax this number will go down and as a result when you have a small heart that
can’t relax there’s not a lot of blood that you can pump out of a small heart
and so therefore what happens in this situation is this will stay about the
same or if it goes down this also goes down and so as a result
the ejection fraction and diastolic dysfunction is about the same
it doesn’t change and this distinction has been made with the new
classification let’s talk about that officially speaking this is the new
terminology there’s something called heart failure due to reduced ejection
fraction and then there is heart failure with normal ejection fraction now if you
notice here is the reduced here is the normal that’s all you really need to
look at you know that if you have a reduced ejection fraction then you have
systolic dysfunction and the problem here is that blood
cannot be ejected out of the heart blood can’t get out as a result of the fact
that blood can’t get out then blood can’t get in to the heart okay now
with a normal ejection fraction what’s the problem here the problem is is that
blood can’t get into the hearts because the muscles won’t relax
when the muscles don’t relax they can’t relax enough to allow the blood to come
into the heart during diastole and so here the problem is is the blood can’t
get in and as a result of the fact that the blood can’t get into the heart the
blood can’t come out of the heart the heart can’t pump that blood out if it’s
not getting in blood can’t get out notice you have the same problems in
both types of heart failure but the key is is the why the reason why you have
heart failure due to a normal ejection fraction is because blood can’t get in
the reason why you have heart failure in a reduced ejection fraction is because
blood can’t get out now what are some of the causes of these things let’s talk
about reduced ejection fraction so things that can cause reduced ejection
fraction would be ischemic heart disease so you haven’t had enough oxygen going
to the heart and as a result of that tissue has died and it’s no longer
functional it’s weak if parts of the whole muscle die you can even have
aneurysms of the heart muscle so ask emic heart disease is classic think of
this in coronary artery disease people that have had cabbage people with
diabetes okay so what’s the problem in normal each action fraction well
remember here is that blood and get into the heart and the reason
why blood can’t get into the heart is because they’ve had hypertension for so
long that their muscles are so thick that they can’t relax anymore so the big
one here is hypertension almost certainly so think of these in patients
with a normal ejection fraction and they’ve got thickened myocardium left
ventricular hypertrophy these people still benefit from lasix
because remember blood can’t get in there for blood can’t get out and if
blood can’t get in it’s going to congest into the pulmonary circulation so the
key that I want you to remember here is if you suspect somebody has congestive
heart failure and you get an echocardiogram and the ejection fraction
is greater than 40 percent you really can’t say that this patient doesn’t have
congestive heart failure because they very well certainly can they would have
heart failure with a normal ejection fraction we’ll talk later about some of
the other aspects of heart failure please join us for our next video thanks
for joining us you you