00:00
Hi! Welcome to our video series
on acute coronary syndromes.
00:05
Now,
we're going to talk about MIs,
Myocardial Infarction
and help you differentiate
between a stemi and a non-stemi.
00:12
So this is going to be really
fun, hang with us.
00:15
Now a myocardial infarction.
00:17
This is just a
quick review for you
because I know,
you probably already know what this is,
but humor me as we
walk back through it.
00:24
Now. You see in our graphic.
00:26
We've got a little area there
and you see the blood
supply of the heart.
00:30
I encourage you if you haven't
spent time studying that
to really refresh your memory
or learn it for the first time.
00:36
But either way,
it's important you understand
the location of those vessels.
00:41
You'll see on the drawing
how their kind of pinking color
that means blood supply
is present there.
00:46
But in the part we've
zeroed in for you see that
there's not blood supply down by
that tissue that's been infarcted.
00:54
Because there's a blockage
that's what a myocardial
infarction is,
but I want you to keep an eye
on these drawings as we go
through this presentation,
because we've done
a really good job
of helping you visualize what
the average heart looks like.
01:06
So you've got it there.
01:07
It's a localized
area of necrosis,
dead tissue in the heart.
01:12
You can tell in the drawing
that there's not blood
getting to that tissue
and that's why it's dead.
01:17
Now it's caused by an
occlusion of a coronary artery.
01:20
That's what you
see blown up there.
01:22
You can see the plaque
that's formed on both sides
and included the artery.
01:27
And when that happens,
you can't get enough
oxygen to the heart
and that that is
why the tissue dies.
01:32
Now if this makes
perfect sense to you,
just celebrate.
01:36
Your learning
stuff all the time.
01:38
And as you continue to
put the pieces together,
it's going to be
more and more fun
as you can apply that
to clinical practice.
01:45
Now with anything stroke
or a heart attack,
Time is tissue!
And the faster we can
re-establish that blood flow
the better chance we have
of minimizing irreversible death
of those cells.
01:58
Usually takes about 20 minutes
of the artery being blocked,
for the tissue to begin
to infarct or to die.
02:05
So we've got about
a four-hour window
the onset of pain of symptoms
that the tissue can be salvaged.
02:12
Now If you've heard us
talk about thrombolytics,
there's a four-hour window
within symptom onset
when that medication
has to be administered.
02:20
This is why,
because if we can restore blood
flow within a four-hour window,
then that tissue is more
likely to be salvaged
after four hours,
we I really don't have much of a chance
which is why we don't
give thrombolytics
because they're a
high benefit drug,
but they're also
high risk since they,
boom, blow up all these cloths
anywhere and indiscriminately.
02:44
So let's talk about
how we name MIs.
02:47
This is why I really
stressed with you.
02:49
It's important
that you understand
how the blood supply works.
02:53
Now this is in a textbook heart.
02:56
I know I've worked when
you see patients results
after a heart cath.
03:00
Not everybody's blood supply
looks exactly like this
but this is the general idea.
03:05
So I want you to take a look and
orient yourself on the graphic.
03:09
You see where the aorta
is you have a feel for,
all those vessels are going
out to the rest of the body.
03:14
We've got the atrium on the top,
the ventricles on the bottom.
03:19
Now locate the left
coronary artery.
03:22
Can you see that there?
Okay good.
03:24
We're going to walk through
how some of these work.
03:28
So underneath there,
We've got these circumflex artery
now that's going in
between those vessels
that you see right near
the top left circumflex
means it's going to
wrap around the heart.
03:41
Now if we have a blockage in
the left circumflex artery,
it's going to be a
lateral or a posterior MI.
03:48
Now in the drawing
we've kind of tried to show you
in this graphic
how it wraps around.
03:54
So you'll see as the vessel
comes around the back
side of the heart.
03:57
It's got a dotted line,
and the artist did that for you.
04:00
So you have a 3D
picture in your mind
of how these vessels wrap
around the cardiac muscle.
04:07
So spend some time.
04:08
Make sure you come back
and really look at these,
if you're not clear,
if you can't name these vessels
from your memory
without looking at notes
just write yourself a
reminder to come back
and really dive in
spend some time
here and make sure
you're very clear and
where these vessels are.
04:25
So we talked about a left
circumflex occlusion.
04:28
That means I've got a blockage
in the left circumflex artery,
but here's the Widowmaker,
left anterior
descending occlusion.
04:37
Find that on the graphic.
04:39
So you see that there look what
it feeds its the Widowmaker
because it has the
highest mortality rate.
04:46
It's an anterior wall damage
that's going to really take
out your left ventricle
and that's why it's such a
significant heart attack.
04:57
All right,
you found the left circumflex.
04:59
We talked about occlusion there,
and how that normally wraps
around the back of the heart,
and you can see that
with the dotted line.
05:05
We've talked about
the Widowmaker
and you found the left
anterior descending artery
if that's occluded,
We have a significant impact
on the left ventricle,
which is responsible
for pushing blood out
to the rest of the body.
05:20
Now finally, we're going to wrap
up with the right coronary artery
so find that in your graphic.
05:26
There you go.
05:27
So a right coronary
artery occlusion
is inferior wall damage.
05:32
So we've used some
different terms here,
lateral, posterior,
anterior and inferior.
05:38
Make sure you have
clear in your mind.
05:39
If you see those words used
and that verbiage that you know,
which artery is involved.