and try to remove that clot and by doing so,
aren’t you addressing both goals?
By decreasing myocardial oxygen demand, we
have beta-blockers, slows down the heart
rate. Remember the two major factors or components
or constituents of your work of the heart
demand depended on heart rate and the ability
to pump. The heart rate when I try to give
a beta-blocker decrease heart rate. Nitrates
what they do? Well, we talked about how you could
have vascular resistance, which has increased,
which it does because of sympathetic activity
and so, therefore, nitrates might cause vasodilation.
Now you tell me, be careful,
how do you decrease your afterload? It is about
working on the arteries, arterial side or
is about working on the venous side? And you
will tell me correctly working on the arterial
side. Good. By doing that, you are then relieving
some of the resistance, aren’t you? And what
about morphine? It decreases the pain and
produce the adrenergic drive with morphine.
What about the supply? Let us give oxygen.
I have to give oxygen. What about that clot?
It is already too big, so when I try to get in there,
get rid of it. You've bust that clot. You call
this as a blood thinner and how important is that concept, vary
in hemodynamics, all the different ways in
which you can bust that clot. Aspirin or aspirin
alternatives including clopidogrel or "Plavix".
A clopidogrel enables your ADP and if your
ADP is not released from your platelet, then
you can't express what? Remember this from pharmacology,
pay attention, you can't express your glycoprotein IIb, IIIa.
You do not have that, you do not have
proper aggregation, do you? Or else might you
want to use something like cilostazol and
a couple of others as well. IV heparin, anticoagulant,
prevents thrombus formation. At some point,
let us say that you want to use a blood thinner
in which you try to bust that clotting and you have coags
or coagulation factors, important options
here including heparin. Heparin works to antithrombin
III as you should know and antithrombin III
is going to do exactly that, knock out thrombin.
Or you have direct thrombin inhibitors, don't
you? And this then brings you to important
topics in drugs such as dabigatran, direct
thrombin inhibitor or apixaban. We have got
a couple of these that you want to pay attention
to. Why? Because you want to try to increase
the supply of oxygen to your dying heart so
that you can then shift over into aerobic
glycolysis and proper ATP production.
Continuing our discussion, nitrates. Now rapid
reperfusion could be an issue. You want to
be careful here. Pay attention. So you had
this clot. How could this clot develop? A
clot was developing and over years and years
and years, and at some point in time, the tissue
distally, so if this is my clot and my tissue distally
became accustomed to that decreased perfusion,
didn't it? And then all of a sudden that clot
became so big and you are going to go in
there and use something like a plasminogen
analog, some type of plasminogen activator
and you gave a tissue plasminogen activator
such as alteplase or what have you, and you bust that clot. My
goodness, gracious. Water is good for you.
But you are doing kind of a fire hydrant, it will
kill you. Now that tissue distal to the stenosis,
drinking all this oxygen all of a sudden, oh!
My goodness, this excess oxygen that has been
introduced into the tissue, you think there
may be perhaps some of their oxygen might
lose electron and become a free radical? Exactly.
What's that called? Reactive oxygen species.
Welcome to rapid reperfusion, but we're specific
referring to reperfusion injury. And
calcium play a huge role. We will talk about
that. All this is to come while you are trying
to do that. You are trying to induce rapid
reperfusion. Here are some of your drugs such
as your thrombolytics, your tPAs and also you try to
go in there and say that the drugs aren’t
working well enough or you want to go in there
and really make sure that you prevent further
thrombi formation and so, therefore, you will
think about using percutaneous intervention
and you either have angioplasty in which you will
try to balloon in and while you're in there, you'll try to place
a stent as well. Worst case scenario, you can't go in
and place a stent, then you have to do bypass surgery.