Okay. Let's talk about some cardiac syndromes and ischemic
So angina pectoris, chest pain. That's what that means or
either way, angina, angina will have kind of three general
So you can have stable angina pectoris.
So that means that you're pretty much here on the scales of
perfusion, demand, perfusion, demand.
Now, if demand increases relative to perfusion,
you're going to have predictably, some degree of angina,
That's associated with that degree of activity. So at rest,
And then I get up and I run around the block once,
and I have chest pain but it's pretty reliable. It happens
at that level.
That's where I've exceeded my balance. So that's a stable
There is Prinzmetal angina which I've described previously,
where you have vasospasm and sometimes,
this can be related to the production of catechols,
Epinephrine, things like that.
Sometimes, we don't know necessarily what's driving that.
And then there's unstable angina.
And unstable anginas, we'll see in a few slides, actually
has three flavors of its own.
So unstable angina means I'm having brand new onset chest
pain that I haven't had before.
So the first onset of something that may eventually become
stable is called unstable angina.
I'm getting chest pain. Previously, I used to be able to run
around the block, no pain.
Now, I ran around the block today, I got some pain. That's
It needs to be evaluated as such. You can have - so that's
You can have progressive angina. So previously, you ran
around the block.
That gave me angina. But now, I run halfway around the block
and I get angina.
That is unstable. It's progressive. It's getting - it's
presenting with less activity.
Or there can be onset of angina at rest. So I'm not doing
I'm not increasing supply or demand or anything.
And suddenly, I've got chest pain. That's a third form of
And all of those, say, "Oh, things are going wrong somewhere
in the coronary artery.
And yet, needs to be evaluated." Myocardial infarction.
This is now beyond chest pain. So chest pain is just like,
you know, it is a shot across the bow.
You need to evaluate why this is happening.
But Myocardial infarction means, now, it's not a shot across
It's a shot into the bow. And this is when the severity or
the duration of ischemia
is sufficient to cause cardiomyocyte death.
And basically, it's cutting off the blood supply to some
portion of the heart
for more than 20 or 30 minutes, and those heart muscle cells
Sudden cardiac death, SCD can occur as a consequence of
tissue damage from a myocardial infarct.
But in the vast majority of cases, sudden cardiac death,
meaning, you die within the onset of symptoms, within an
hour or so of onset of symptoms,
is not usually a consequence of a myocardial infarct
but is most commonly a lethal arrhythmia due to myocyte
ischemia but not myocyte necrosis.
It can be due to an infarct.
But again, more commonly, 90% of cases are going to be due
to a fatal lethal arrhythmia.
And then you can have chronic ischemic heart disease with
congestive heart failure.
So you can have an acute MI, damage part of the muscle.
You don't die from it, but now, the compensatory mechanisms
of the residual
viable myocytes try to hypertrophy, try to maintain cardiac
output and over a period of time, they fail.
And if you want to learn more about congestive heart
failure, that's another talk.
But anyway, so that can be one mechanism.
The other one is you can have tiny little ischemic insults
that just like death by a thousand papercuts,
eventually cause dysfunction and congestive heart failure.