00:00
Now, again,
we talked about the different kinds
of heart failure
systolic and diastolic.
00:06
But sometimes there are
definitions based upon
which ventricle is
in the most trouble.
00:13
Most common is
left-sided heart failure.
00:15
That's because the left
ventricle has been injured.
00:18
But in some conditions such as severe lung
disease with high pressures in the lung,
you may just see isolated,
right-sided heart failure.
00:28
So let's think about
this for a moment.
00:29
With left-sided heart failure,
the backup is going to be into the lungs.
00:34
Patients get fluid in the lungs,
and they're short of breath.
00:37
So the edema is in the lungs
with left-sided heart failure.
00:40
With right-sided heart failure,
the backup is into the veins.
00:44
So you often see patients
with fluid in the abdomen,
fluid in the in the legs,
so called peripheral edema.
00:53
And the left ventricle may be working
just fine but it's not getting any blood
from the right ventricle because
the right ventricle is failing.
01:01
And of course, it's obvious.
01:03
What the left ventricle puts out depends
on what the right ventricle puts out.
01:06
If they have to balance out,
if they don't balance out,
all the blood is going to end up on one
side of the circulation or the other.
01:13
And then we've talked about before systolic
heart failure, failure of contraction.
01:17
Diastolic heart failure,
failure of relaxation.
01:21
Patients with chronic heart failure can
be divided into two broad categories
based on whether their ejection
fraction is normal or reduced.
01:30
These two categories are heart failure with
preserved ejection fraction called HFpEF,
and heart failure with reduced
ejection fraction called HFrEF.
01:40
Sometimes the third
category is implied and used
and that's heart failure with mildly
reduced ejection fraction of 41 to 49%.
01:49
Because normal, of
course, is above 50%.
01:52
For the most part,
it's important to know the differences
between the two distinct
types of heart failure.
01:58
About half of the patients
with heart failure
have HFpEF and about
half have HFrEF.
02:03
This distinction
has prognostic value
and it also helps guide therapy for
the patients with heart failure.
02:09
Since therapy is different
for HFpEF and HFrEF.
02:13
HFpEF is defined as a left
ventricular ejection fraction
of 50% or more in a patient with signs
and symptoms of clinical heart failure.
02:22
Although most patients with
HFpEF have diastolic dysfunction
with elevated filling pressures.
02:27
Asymptomatic diastolic
dysfunction can be seen
with normal aging in individuals
who do not have clinical symptoms.
02:35
So although people with diastolic
dysfunction have a risk factor for HFpEF,
these two terms
are not synonymous.
02:43
HFpEF must be distinguished from
other causes of heart failure
in patients with an ejection
fraction greater than 50%.
02:50
And these include patients with valvular
heart disease, pericardial disease,
cardiac amyloidosis,
and high-output heart failure,
such as that seen with severe
anemia or hyperthyroidism.
03:03
Heart failure with reduced
ejection fraction or HFrEF
is defined as a left ventricular
ejection fraction less than 50%.
03:11
Although an ejection fraction
in the 40s is sometimes
called mildly reduced
ejection fraction.
03:17
Patients with HFrEF
have difficulty
with the pumping function
of the left ventricle,
the heart and by definition, a reduced
ejection fraction in the left ventricle
known as impaired
systolic function.
03:32
Decreased ejection fraction leads
to inadequate tissue perfusion,
and of course influences the
prognosis of the patient.
03:39
As you might expect,
the lower the ejection fraction,
often the worse the patient does
and the more symptoms they have.
03:46
Cardiac remodeling is a
response to hemodynamic load
as well as neurohormonal
activation.
03:53
Pathological remodeling can
be seen with pressure overload
due to hypertension
or aortic stenosis
can also be seen with volume
overload with valvular regurgitation,
or with cardiac injury, for
example, myocardial infarction.
04:08
The management of HFrEF is quite
different from the management of HFpEF.
04:13
And it's important to
know the differences.
04:17
Here's just a little
diagram to remind you
how the whole body is
a coordinated system.
04:22
You see the brain is
connected to the heart.
04:25
The brain is connected
to the kidneys.
04:27
They're all connected to the
peripheral blood vessels.
04:30
And as we've talked about,
when there's heart failure,
or when there's dehydration
or when there's hemorrhage,
all of these factors become activated in
an attempt to (A) restore the blood volume,
and (B) restore the pumping
ability of the heart.
04:46
And here they are
all listed again.
04:48
Just as as we've
talked about before,
the central nervous
system is critical.
04:53
The sympathetic nervous
system is activated,
the kidney through the
renin-angiotensin system is activated.
05:00
And the ventricle gets increased volume
and therefore uses the starling mechanism.
05:06
All of these things
work together.
05:08
They work great if the
patient's blood volume is down
because of dehydration
and hemorrhage.
05:13
They work against you when the problem
is that the heart is not pumping enough.
05:18
And again, here you see a diagram that
just shows you how all of these interact,
how the decreased cardiac output
can lead to lung congestion,
and how increased peripheral pressure
can lead to peripheral edema,
the neurohormonal activations
through the kidney that go on.
05:40
All of these things are
working in a complete
circus motion like a horse riding
around the track in a circus,
around and around they keep
reinforcing each other.
05:53
And unfortunately, in heart failure leads
to marked retention of water and salt
that leads to the various symptoms
that the heart failure patient has.
06:03
And the American Heart
Association guidelines
talk about various
levels of heart failure.
06:09
Level A is somebody who's really
predisposed to heart failure
but has not developed it yet.
06:14
So that's somebody with high blood
pressure, diabetes, hypercholesterolemia,
hyperlipidemia, as we've talked
about, that leads to atherosclerosis.
06:22
Heart failure hasn't
developed yet,
but the substrate if you will, is ready
to go on and cause a heart condition
that will lead to heart failure.
06:30
Grade B is when you're
starting to have some very
early signs of heart failure
by some of our fancy tests,
such as from the echocardiogram,
but the patient is still asymptomatic.
06:43
Stage C is when the patient
is already having symptoms.
06:46
They're tired, they're short of
breath, they have peripheral edema,
and stage D is when they're
really incapacitated
with heart failure marked severe
symptoms of heart failure.