What is going on guys? Don checking in, welcome to MINT, where we bring nursing to you.
So today, we are going to talk about the easiest way to interpret your PVCs but,
if you haven't already, I highly recommend that you guys check out
our EKG video. It will give you basic knowledge about how to interpret your
EKGs. You guys got your notes ready? Cause I'm ready. Let's go.
Hello guys. We are going to talk about PVCs. A PVC is an example of a premature complex. Note
the word, "premature". These premature complexes tend to fire earlier than normal. They can be
considered to be the "hiccups" of your heart rhythm. So what exactly is a PVC? PVC stands for
“premature ventricular complex”. So this is your heart without the PVC. Your conduction goes from
the SA node, all the way to the Purkinje fibers and then it generates a normal heart rhythm. However,
this is your heart with a PVC. This is your premature ventricular complex. They
originate here within the ventricles. So what is happening within the heart when
PVCs occur? Let's take a look. Here, where there is no PVC, the reading will look like
your typical EKG. So when the impulse goes from the SA node all the way to the Purkinje fibers,
it will generate a normal P wave right here, as atria contract,
your QRS complex, as ventricles contract, and a T wave as ventricles relax. However,
your EKG will look something like this if you have a PVC. When the ventricles initiate a PVC,
meaning this complex right here will fire early, you will have a bizarre looking QRS complex.
So let's talk about the key characteristics of a PVC. Your PVCs are usually wide and
bizarre-looking, as you can see right over here. Another characteristic of a PVC is that, usually,
these are followed by a compensatory pause right over here. The pause allows the underlying rhythm
to continue again at its normal rate as if the PVC never occurred. So the way we are going to
interpret your EKG with premature complexes is that you look for the compensatory pause. When
you find the pause, you go back to the rhythm prior to the pause. If you see a
bizarre looking QRS complex that fired early, this indicates a PVC. Let us now discuss the
different classifications of PVC. We classify PVCs based on the site of origin and the frequency of
occurrence. Let's talk about the site of origin. Under this classification, we have what we call
a unifocal PVC. Unifocal PVCs originate from a single site within the ventricles,
right over here. If your PVC is coming from a single site, your EKG will look something like
this. As you can see, the QRS complex of unifocal PVCs look alike; same shape, same size. Therefore,
unifocal PVCs are also known as monomorphic PVCs. On the contrary, we have another classification
called multifocal PVCs. PVCs originate from different sites within the ventricles,
right there. When you have multiple complexes within the ventricles, your EKG will look something
like this.The bizarre-looking QRS complexes have different sizes and shapes. That is why multifocal
PVCs are also known as polymorphic PVCs. So now let's talk about the frequency of occurrence of
PVCs. In this classification, we are looking at how often these PVCs occur. This usually
tells us how irritable the cardiac cells are. First term to remember for this classification
is quadrigeminy. Quadrigeminy PVCs occur every fourth QRS complex or every fourth beat. The EKG
looks like this. As you can see, your compensatory pauses are still here and if you look at the prior
rhythm, you have a bizarre looking QRS complex. And now we are going to count. One, two, three,
four. There's your PVC. One, two, three, four. There's another PVC. So it's every fourth QRS
or every fourth beat. This is quadrigeminy PVC. Next term is trigeminy. So your key word here is
“tri", which means every third QRS complex will have a PVC. This is your trigeminy PVC EKG. So
you have your compensatory pauses right here. And let's go ahead and count. One, two, three.
There's your PVC. One, two, three. There's your PVC. One, two, three, so every third QRS complex
or every third beat, you have a PVC. This is your trigeminy PVC. And last one is your bigeminy PVCs.
By its name, “bi”, this means that every second beat or every other beat is a PVC. This is what it
looks like. So your compensatory pauses are still here and your PVCs are also there prior to the
pauses. Let's count. One, two, PVC. One, two, PVC. One, two, PVC. One, two, PVC. So every other beat,
there's a PVC. So let's go ahead and do a quick review. The site of origin pertains to unifocal
PVCs, where the complex originate from a single site causing PVCs complexes to have a
uniform shape and size. The next one is multifocal PVCs where the complex originate from multiple
sites within the ventricles, causing PVC complexes to have different shapes and sizes. For frequency
of occurrence we have quandrigeminy, where in the PVC occurs every fourth beat. Trigeminy,
where PVC occur every third beat. And lastly is bigeminy where PVC occur every other beat.
That being said, let's go ahead and apply these two classifications together to name our PVCs. We are
going to practice reading EKG strips. First one is this. So the first thing that we're going to do is
look for the compensatory pauses. There's our compensatory pauses. Now, we look at the rhythm
prior to these pauses. So we have your PVC right here and your PVC right over here. Now if you look
those two QRS complexes, they have different sizes and shape. Meaning, this is a multifocal
PVCs. Now let's count 1,2, 3. 1, 2, 3. So it's every third beat. We have to remember that
when we're naming our PVCs, we also take into consideration the underlying rhythm. So what is
this rhythm? This is what you call a sinus rhythm with multifocal trigeminy PVC. Multifocal because
there are QRS complexes with different sizes and shape and trigeminy because it's happening
every third beat. Let's go to another example. And we're looking at the
compensatory pauses. Now we look at the PVCs. These PVCs are the same size, the same shape.
So this means that this is a unifocal PVC. Now let's count. 1, 2, 3. 1, 2, 3, 1, 2, 3. It’s happening every
third beat. That means it's a trigeminy. And because the underlying rhythm is sinus rhythm,
This is sinus rhythm with unifocal trigeminy PVCs. Unifocal because the same size
and the same shape, trigeminy because it's happening every third beat. Let's go to another
example. Now let's look for the compensatory pauses. There they are. Let's look at the QRS
complexes, wide and bizarre, same shape, same size. So they are unifocal PVCs. Let's count.
1,2. 1, 2. So it's every other beat. This means that this is sinus rhythm with unifocal bigeminy PVCs.
Unifocal, the same size, bigeminy, every other beat. How about this? Compensatory pauses,
compensatory pauses, PVC, PVC, PVC, PVC. Different size, different shapes. So this means,
that it is a multifocal PVC. Now let's count, one, two, one, two ,one, two. So what could this be?
This is sinus rhythm with multifocal bigeminy PVC. Multifocal because they have different
sizes and different shape. Bigeminy because it's happening every other beat. That's it.
That is it for today guys. I hope you guys found that video helpful. If you haven't already,
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upload new videos. Once again my name is Don, MINT, signing out. Oh, stay home and stay safe.