What is going on guys? Don checking in. Welcome to MINT, where we bring nursing to you.
So today we're going to talk about the easiest way to do your EKG interpretation.
So if you're a nursing student or a new nurse who wants to do your EKG faster,
stick around this video is for you.
Alright guys this is the six-step EKG interpretation. So before we talk about the actual
steps, we're gonna discuss important concepts that will help us have a better understanding of what's
going on inside the heart, as it generates a heartbeat. The first concept that we are going to
discuss is the conduction system of the heart. Now the conduction system of the heart is pretty much
these special cardiac cells right here that are responsible in conducting signals that cause the
heart to contract. The first cell is called the SA node, right here or the sinoatrial node. By its
name sino "atrial", this cell is found within the right atrium of the heart. This is also known as
the natural pacemaker of the heart, because this is where the beginning of the conduction takes
place. So from the SA node, the conduction goes to the AV node or the atrioventricular node. By
its name, this can be found within the border of the right atrium and the right ventricle. The AV
node is also known as the gatekeeper of the heart and the reason being is that it gets to decide
whether what impulse to let through. So if the SA node generates a weak impulse or there is a block
here somewhere, the AV node will perceive that and will decide not to let the impulse go through and
instead it will conduct its own impulse. So from the AV node, it goes through the single structure
right here called the Bundle of His. And from the Bundle of His, the cells will continue and
will bifurcate into two separate cells; one to the left and one to the right. And this will now
be called the Left and Right Bundle Branches. And from the bundle branches they will extend within
the apex of the heart. They will be called the Purkinje fibers. So again the conduction system
of the heart begins at the SA node, goes to the AV node, next is the Bundle of His,
the Right and the Left Bundle Branches and then eventually Purkinje fibers. So another concept
that we need to discuss will be the inherent rate of these cardiac cells. When you say inherent
rates , these are pretty much the heart rate that we generate depending on which cardiac cell sends
an impulse. So for example, if the SA node starts it all and it goes all the way to the Purkinje
fibers, this will generate a heart rate of 60 to 100 beats per minute. It starts from here,
goes all the way to the Purkinje fibers, that will generate a heart rate of 60 to 100 beats
per minute. However, for some reason, if the SA node fails or there's a block somewhere here,
then the AV node will kick in. It will generate its own impulse. And when this happens the AV node
will generate a heart rate of 40 to 60 beats per minute. And that also includes the Bundle of His,
the Bundle of His also will generate its own impulse and it's enough to make 40 to 60 beats per
minute. And if the AV node or the Bundle of His fail, then the Left and the Right Bundle Branches
and the Purkinje fibers will generate their own impulse and they have the capacity to make a heart
beat up to 20 to 40 beats per minute. So now let us talk about EKG it has different parts. We will
start with the small bump right here called the P wave, followed by this tall structure right
here called the QRS complex and lastly the last bump after the QRS complex will be the T wave.
Let us discuss them one by one. Let's start off with P wave. The P wave represents atrial
depolarization. During atrial depolarization, the two atria are contracting. Next up,
the QRS complex. Now the QRS complex represents ventricular depolarization. During ventricular
depolarization, the ventricles of the heart are contracting. Depolarization is for contraction. So
how would you know which one is which, that P wave is for atria while QRS is to ventricles? So if you
look at the diagram right here, the QRS complex, it kinda looks like an inverted "V" so "V" for
ventricles. So when you see a QRS complex, think about ventricular depolarization. So lastly, we
have the T wave. The T wave represents ventricular repolarization. This is when the ventricles are
relaxing. Keep in mind that every depolarization is always followed by repolarization. So for every
contraction will be followed by relaxation. That being said the question is, where is
atrial repolarization? So if QRS represents ventricular depolarization or contraction and
T wave represents ventricular repolarization or relaxation, then where is atrial repolarization
if this is depolarization? Well it can be found within the QRS complex. As you can see, the QRS
complex it's a tall structure. Because ventricles tend to contract stronger than the atria,
they tend to mask the atrial repolarization. And so that being said, atrial repolarization
and relaxation takes place after the P wave, which can be found within the QRS complex.
Now as a review, P wave stands for atrial depolarization. The QRS complex represents
ventricular depolarization. The T wave represents ventricular repolarization. And the atrial
repolarization is covered by the QRS complex. You can't see it but it exists. So now let us
talk about the segments and intervals in the EKG diagram. There are a bunch. Starting off with a PR
interval, the PR segment, the QRS complex, the ST segment, and the QT interval. But to make it easy
for you guys we are just going to talk about the PR interval and the QRS complex. These are
all we need to do the EKG interpretation. The other segments, they are important too but we
don't really need them to interpret the EKG faster and more efficient. So, this is your typical EKG
strip. In an EKG strip, we have a big box. And inside a big box, we have five small boxes. Each
small boxes is equal to 0.04 seconds. And so if in a big box there are five small boxes, that means
that one big box is equal to 0.20 seconds. But really, as long as you know that one small box
is 0.04 seconds, we're good to go. So let us get on with our six step EKG interpretation. First up,
we have to identify and examine the p-waves, measure the PR interval, measure the QRS complex,
identify the rhythm, determine the heart rate, and interpret your strip. And we're going to
talk about them one by one. Let's start off with identify and examine your P waves,
right here. The normal P wave would be present and upright. If the P wave is absent or inverted,
then it could indicate a form of dysrhythmia such as a junctional rhythm. Next up we are
going to measure the PR interval. PR interval is the distance between the beginning of the P
wave and the beginning of the QRS complex. What we do, is we count the number of small boxes in
between and multiply it by 0.04 seconds. Our magic number for the PR interval is 0.12 - 0.20 seconds.
Anything more than 0.20 seconds could indicate another dysrhythmia such as heart blocks. Third
would be to measure the QRS complex. Just like the PR interval, we are going to measure the
small boxes in between the QRS complex. Our magic number is 0.06 to 0.12 seconds. Anything more than
0.12 could indicate a dysrhythmia such as a PVC. Number four, is we have to identify the rhythm of
our strip. It could be regular or irregular. And the way we do this, is we measure the
distance between R's; R's and R's. Some people use calipers to do this, but really all you need is an
index card mark your R's and march them with the rest of the R's. If they have the same distance,
then your rhythm is regular. Otherwise, they are irregular. Fifth step is when we identify
our heart rate. Now before we calculate our heart rate, it is very important for us to know that our
EKG is a 6 second strip. And the way we will know this, is when we find these three lines right over
here. If you see these lines, this means that from the first line up to the third line, that
would be your 6 second strip. The reason why this is important is that if it is a 6 second strip,
then we can do a technique called the 6 second method. And the way we do this is that we count
the number of R's between these three lines right here and multiply them by 10. So for this strip,
we have 1, 2, 3,4, 5, 6 and multiply that by 10. That will give us a heart rate of 60 beats per
minute . One thing to remember is that this method works best for irregular rhythms. And another tip
that I can tell you is that you have to be very very careful in using the 6-second method. You
always have to verify that the strip that you're reading is indeed a 6 second strip. I know some
teachers include strips that appear to be 6 second strips but they're really not. They don't
have these three lines right here and students actually mess up the heart rate because they use
the 6 second method . This method only works for 6 second strips. Okay, second method that we can use
to calculate the heart rate is the big box method. And the way this works is that we divide 300 by
the number of big boxes between two R's. Our magic number is 300. So for this strip, we are going to
use these two R's right here. So we have 1, 2, 3, 4, 5 big boxes in between R's and so using
the formula, 300 divided by 5, we have 60 beats per minute. This method works better for regular
rhythms only. And this is actually the method that you can use if you don't have a 6 second strip in
front of you. And the final step is, interpret your strip. So that is it for today guys. I hope
you find that helpful. And if you haven't already, please hit the like and subscribe button. And let
us know in the comment section below if you want us to make videos about dysrhythmias
such as heart blocks or junctional rhythm. And once again my name is Don, MINT, signing out.