Hi, welcome to our video series.
In this one, we're going to look at coronary
artery disease and specifically atherosclerosis.
Okay, that one's a mouthful but I want to
walk you through this simple steps of the changes
that happened in someone's
body with coronary artery disease.
So we always we start with the definition, it's a
great kind of of solid foundation point to start on.
So coronary artery disease you'll see us shorten it to CAD,
it's caused by atherosclerosis so that's how they're aided.
so the atherosclerosis is actually
the most common type of heart disease
so most people as they age
develop some level of this atherosclerosis.
Now what the problem is is we have
arteries that supplies blood to the heart.
That part's not the problem but in coronary artery
disease, you start to have some issues with narrowing,
the vessels become hard or even blocked to the
point that the oxygen-rich blood flow is compromised.
When I say that, that means there's not enough
blood that's got the oxygen the heart muscle needs
getting to that heart muscle,
that's when we have a problem.
So let's take a look at that.
We've given you a good graphic there I
love this picture to help you kind of peek inside
what's going on the artery.
So take a look at the picture on the left.
You see that we've got the long piece of
the artery there, but then we've sliced it in half
so you can see the endothelium.
Okay now, around the endothelium
we've got the smooth muscle.
Look at it in both pictures.
See that, it's right in the walls of the vessels.
So here we've got a long section there, we've got
a slice like a little carrot-sized slice of your vessel,
so see where there's smooth
muscle right in the wall,
and hardening and narrowing of these arteries
is what causes the problem of your patient.
Now you have this hardening, the
narrowing because you got a buildup of plaque.
Now plaque is that kind of the
yellowy stuff that you see there.
So in the very early part of that
long piece, you see it looks really clear
but as you move down toward the end closest
to us, you see that we've got lipids and calcium
and all kinds of cellular debris there.
That's what gets really hard and stiff eventually.
You can tell how it narrows the
space that the blood has to flow through.
Look at the drawing on the right.
That atherosclerosis, has almost
cut that vessel's capacity in half
and that's one of the reasons why atherosclerosis
can be so difficult for a patient's body to adjust to.
So how do we end up in this state?
Well I want to walk you through step-by-step
what happens over relatively long period of time
but we're just going to speed it up.
Now look at the heart there, you
see that we got kind of that black area?
That's to remind you that that's an area where an
occlusion happened, where it's been completely blocked off
and the surrounding muscle tissue is damaged.
The reason it's damaged is because it
blocked off the hearts supply to the muscle.
So start at the top in our vessels.
You have a normal artery, then it has kind of an
early injury, start to have the atherosclerosis build-up,
and the bottom one is a complete blockage.
That's what leads to that
damaged or infarcted tissue.
Well at the first three vessels we see normal, early
injury and then you see the atherosclerosis building up.
What happened in the bottom one?
Some type of clot broke off, floated to the
system and it got to a narrowed part of the artery
because of atherosclerosis and
completely blocked off the blood supply.
So that's how we fast forwarded through that,
now let's break down some of the teaching points.
so we know that atherosclerosis member sclerosis
means "the hardening", athero- refers to the vessels
So kind of file that away in your medical
vocabulary to help you sort through other words
when they appear with those
same suffixes or the beginning parts.
So hardening and narrowing of the
arteries is caused by a build up of plaque,
and you saw how that happened from normal artery,
then first having early injury then you have the response
and then it becomes hardened and that's when we
have the partial blockage which could lead to complete.
So it's a chronic inflammatory
process, that's what happens.
So you got the normal, now you see the early injury.
Write in there, chronic inflammation.
So I want you to have that in your mind that
that's one of the things we really try to combat
in all patients so we to try to minimize inflammation.
Now we'll talk about the processes
that we use to do that later.
but I want you to have established in your mind it's
a chronic, meaning it happens over a period of time
and start with damage to the endothelium.
Now a complete blockage could be sudden, right?
but it's because the damage has been done to those
vessels over a period of time - that's the chronic part
that you can end up in a high-risk event like
complete blockage or myocardial infarction.
Now here's what happens, here's what gathers there:
You've already guessed that in your
mind, you know it's an inflammatory process,
but the LDLs - now in case that word's not
familiar to you, that's a form of cholesterol -
The LDLs crossed the damaged
endothelium into the wall of the artery.
So we've got it to just shortcut for you over
there, talk about early injury and then atherosclerosis.
Breaking that down for you what
happens after that early injury.
So these LDLs cross the damaged
endothelium into the wall of the artery.
Now what happens is over time, this
cholesterol becomes part of the plaque.
So you have increased circulation?
The circulation can become compromised
because these LDLs that have crossed over there,
they become part of the plaque -
thats what narrowed the arteries.
So these patients have a higher risk of a cardiovascular
event, an MI - a myocardial infarction, or a stroke.
Now we've been very careful to lay these concepts
down because you need to understand these concepts
when your patient start showing new symptoms.
Knowledge of understanding how atherosclerosis
happens will help you when you're diagnosing how severe,
the type of pain and symptoms
your patient's experiencing.