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.
Thank you for this!