Welcome to the NRSNG Podcast – the podcast created by nurses, for nurses. Are you
ready to take your learning to the next level? Sit back, and crank up the volume. Here’s
your host, Jon Haws.
This is Jon, welcome back again to another podcast episode of the NRSNG.com
podcast. Today we’re going to be talking about 5 step interpretation of EKGs and how
you can quickly identify and analyze these rhythms to identify the rhythm that you are
seeing on the monitor or on the EKG strip.
We will be giving away a free EKG PDF chart that will help you have a quick reference
sheet to all the different rhythms that you need to know and the different criteria for each
of these 5 steps. If you want that chart, go to NRSNG.com/EKG-chart and you can get
that chart for free.
Lets go ahead and start.
First, to be able to quickly identify rhythms you need to understand very briefly how
electrical impulses travel through the heart. Every electrical impulse should start from the
SA node (sinoatrial node) which is located on the top of the right atria and that should
initiate an impulse that will then travel down to the AV note (atrioventricular node), which
sits in between the atria and the ventricles. That’s going to hold the impulse for a minute
before it then travels down to the bundle of His and then to the Purkinje fibers, which will
then depolarize the ventricles.
Start at the SA node, go to the AV node, travel down the bundle of His and then Purkinje
fibers, to depolarize the ventricles. That’s the normal mode of transportation.
Within the heart, we have three different pacemakers that will set the rate for the heart.
The first one is the SA node, as we talked about, the sinoatrial node that sits on the right
atria. That’s going to initiate an impulse every 60 to 100 times per minute, that’s why our
normal heart rate is going to be 60-100. Next, if the SA node isn’t able to fire, the AV
node can actually initiate impulses, 40 to 60 times per minute. If that ultimately fails, then
you have the Purkinje fibers that can also initiate their own impulse at 20 to 40 beats per
minute. That’s why it’s important that we understand the normal heart rate is 60 to 100
and analyze anything that is below that. We want to know if the person is bradycardic for
reasons other than just being athletic or an extreme resting state. If they are not initiating
impulse in the SA node, we need to know where that impulse may be coming from and
further analyze that.
There’s a couple complexes and waves that we are going to identify on a rhythm strip.
First we have our P wave, we have our Q wave, R wave, S wave and T wave. There are
a few more waves but these are the ones that we are going to identify; P, Q, R, S and T.
And then we have our PR interval, which goes from the beginning of the P-Wave to the
beginning of the QRS complex. And then we also have our QRS complex – the QRS
complex makes up the QRS waves and that’s going to identify ventricular depolarization.
For our needs in identifying our rhythms quickly, we’re going to look at our rate, our P
wave, our QRS complex, our PR interval, and the P to QRS ratio.
P wave is going to identify atrial depolarization.
QRS complex represents ventricular depolarization.
PR Interval represents the onset of atrial depolarization to the onset of ventricular
The five things again that we are going to identify to interpret our rhythms is going to be
our (1) rate, (2) P waves, (3) our P wave to QRS complex ratio, (4) our QRS complexes
and (5) our PR interval.
A normal rate is going to be 60 to 100 beats per minute. There’s a couple ways to
identify what your rate is. If you’re looking at a 6 second EKG strip then you can just take
the amount of beats in the 6 seconds and multiply it by 10. If you don’t have a 6 second
strip or you want to get a little more accurate, then you can identify your R waves or your
P waves, count how many large boxes are between those and divide 300 by that
number. So for example, if you identify your R waves and you note that there are 6 large
boxes between those two R waves, then your rate is going to be 50 beats per minute.
Next thing after rate that we’re going to look at is our P waves. We want to notice that
there are P waves present, that they are upright and that they are smooth – that they
aren’t jagged or sharp. So we want P waves to be present, we want them to be upright
and we want them to be smooth.
Next we’re going to notice if we have QRS complexes. We want to notice if our QRS
complexes are present and we want to count the number of small boxes between our Q
and our S. We want there to be 1.5 to 3 small boxes between our Q and our S waves.
So we want present QRS complexes and we want 1.5 to 3 small boxes between the Q
and the S.
Next we want to notice the P to QRS ratio. We want there to be a P wave before every
QRS and we want there to be one P wave for each QRS. So there needs to be a P wave
for every QRS and the P wave needs to come before the QRS complex.
The last thing we’re going to identify in our 5-step method is going to be our PR interval.
Know, the PR interval starts at the beginning of the P wave to the beginning of the QRS
and we want there to be 3 to 5 small boxes. So you’re going to count the number of
small boxes between those two and you want there to be 3 to 5 small boxes.
So first, rate, then P waves, then QRS, then P to QRS ratio and then PR interval. That’s
how we’re going to identify our rhythms.
One more time, we’ll go through it.
We want to identify our rate. We want our rate to be between 60 to 100 beats per
minute. We want to then look at our P waves. We want there to be present P waves, we
want them to be upright and we want them to be smooth. Next we’re going to look at our
QRS, we’re going to make sure that there are QRS complexes, that they are 1.5 to 3
small boxes between the Q and the S. Then we’re going to notice our P to QRS ratio, we
want that to be a 1:1 ratio for every P, there is a QRS and the P comes before the QRS.
Then we are going to look at our PR interval. We want that PR interval to be about 3 to 5
So as you go through these checklists as you look at a rhythm, you can quickly start
identifying what the rhythm is and you can start eliminating specific rhythms based on
each of these criteria. First of all, if you look at your rhythm and your rate is 150, you can
already eliminate sinus rhythm, because it’s greater than 100. If you go there and look at
your PR interval is greater than the 5 boxes you’re going to start looking at some of your
heart blocks – that the impulse is being held in the AV node too long. If you start seeing
the P waves are either absent or going downward rather than upward and smooth, you
might start looking at junctional rhythms.
To really understand this, I really recommend that you go to NRSNG.com/EKG-chart
and you just download that free chart. That will really help you look through the criteria
for each of the different rhythms that you are looking at and give you kind of a practice in
identifying rhythms and working through these 5 criteria. But if you work through these 5
criteria, you’ll be able to identify any rhythm and quickly be able to rule out specific
arrhythmias, and determine if its sinus rhythm or it may be more of a lethal rhythm or if it
might just be a little nuance that you may not have seen if you haven’t worked through
these 5 steps.
So that’s going to be my suggestion. This is just a quick podcast on what you’re looking
at. We aren’t really going to go into the different arrhythmias here, and we may go into
that later. But with every strip that you look at, first look at rate, look at P waves, look at
your QRS complex, look at your P to QRS ratio then look at your PR interval. We also
have a video on YouTube about this. Our channel is NRSNG Com. Check it out – Kevin
has a video and looks through a couple strips in his examples. Best way to do it though
is go to that NRSNG.com/EKG-chart and that will help you identify these rhythms. I
appreciate you listening and we’ll talk to you soon.
Visit us at NRSNG.com for disclaimer information and to keep the learning going.