ECG Interpretation Practice – Pericarditis on EKG Explained!
13
October

By Adem Lewis / in , , , , , , , , , , , , , , , , , , , , , , , , , , , /


well welcome to another MedCram
lecture we’re gonna go over an EKG what we’re gonna do first is we’re gonna go
over the methodology here and that is this order of rate rhythm access
hypertrophy and looking at ST segments so let’s first of all look at the rate
on this EKG so the first thing that I want you to notice specifically here is
at the bottom we can see here is the criteria for what is set the speed of
the EKG is at 25 millimeters per second which is pretty standard what’s not
standard is the 20 millimeters per millivolt and you can see here that that
standardization box is about twice as high as it would normally be so just
keep that in mind and be aware of that so the first thing we want to do is look
at the rate now just by looking at this EKG you can tell right off the bat that
the spaces between the QRS complexes at the beginning are different than at the
end so there may be a rhythm change and anytime we’re this sort of this
irregularity remember that this is a 10 second strip so because there are six
ten-second periods in a minute we can just simply count these up 1 2 3 4 5 6 7
8 21 22 23 and multiply that by 10 so if we have 23 QRS complexes and we multiply
that by 6 since there are 6 10-second periods in a minute we’re gonna get
something that’s close to about 138 beats per minute okay so that would be
the average for the whole EKG now if we go back and look a little bit more
carefully we can actually do it a little bit different methodology well look here
at the beginning and you can see clearly here that we’re dealing with 1 2 3
approximately 3 boxes and you know that the first box is 300 and the second box
is 150 and third box is a hundred so the distance between here and here would
lead you to believe that we’re dealing with about a hundred about a rate of a
hundred okay whereas over here you can see that the number of boxes in between
each is about two boxes and so what we’re dealing with here is about a
hundred and fifty so 150 means that we went from a hundred to about a hundred
and fifty and as you can tell as we’ll get into a little bit later we may have
got into any regular rhythm but let’s keep an eye on that so I think here
overall we went from about a hundred to 150 based on the boxes but the average
looking at all of the beats would be 23 times 6 which is about 138 so that would
be the average about 138 beats per minute so that’s the rate the
ventricular rate okay let’s look at rhythm next so for rhythm we’re looking
at P waves and QRS complexes and we’re also looking at seeing how regular
things are you can see here at the beginning things generally speaking are
pretty regular whereas here at the end we’ve got some irregularity you can see
here for instance the distance between here is a little bit different than the
distance between here there seems to be a speeding up and I think what you may
see here if you look very carefully is some P waves there and then there may be
some in here and also in here or it could be just the end of the QRS complex
if there is there’s definitely a distance between these two and it’s
almost getting to be a first degree heart block
certainly here one can make the argument about that either this is a speed up
here and this goes into like intermittent atrial fibrillation with
sinus rhythm here I think one can definitely make the argument that we are
definitely in a sinus rhythm here at the beginning but in terms of the rate you
can see here that certainly the distance here is different than the distance here
so we may be dealing with the intermittent atrial fibrillation versus
a fluctuating sinus tachycardia and I know that later after this patient have
this EKG the patient did go into atrial fibrillation so again I think what we
can say here is we certainly started out in sinus but it ended up going into
atrial fibrillation although it’s not particularly clear on that okay next is
access so what I like to do with access and I’ll pick a different color here so
you can see is there’s a number of techniques that you can use one of the
techniques is looking at these limb leads and picking out the one in this
case it’s Roman numeral one that is the highest positive amplitude and that’s
going to be the one that is going to have the direction that most likely goes
along with the axis so because the vector Roman numeral one is in this
direction that’s going to be the direction generally speaking of the axis
now that could also mean that since a VF is going
down that it should be the most isoelectric and in fact that’s exactly
what we see is here in AVF we’re seeing the least amplitude so therefore the
axis has to be most in line with lead room numeral one and perpendicular to
lead a VF since that has the lowest amplitude out of all of them so let’s
see what that would look like it would look like then that the vector would
have to be going in this direction why is that because it’s most in line with
Roman numeral one and it’s perpendicular to a VF so if that’s the case if we were
to look at for instance Roman numeral two or even three if the vector is in
fact going from left to right on the page but actually left axis deviation
because we’re looking at the patient then it should be negative in Roman
numeral lead three and positive in Roman numeral lead to right because it’s going
generally in the same direction as two but it’s going the opposite direction as
three so let’s take a look and see if that’s in fact the case and sure enough
we see in Roman numeral lead three we have a negative deflection and in Roman
numeral two we have a positive deflection so that makes sense we also
see a relatively positive deflection in AVL now why would that be again looking
at this AVL goes in this direction and that’s almost generally speaking the
exact same direction as the vector that we’re proposing so I believe here that
some perturbation of this is gonna be your axis going from basically it’s
almost to the left axis deviation a slight left axis deviation
okay so we got rate rhythm and we got access let’s look for hypertrophy now
hypertrophy is tricky as you’ll know well let’s look back here and there’s
four chambers of the heart let’s go through them there’s the right atrium
the left atrium the right ventricle and the left ventricle so if we’re looking
for right atrial enlargement the big thing that we look for is two things
number one we live for peaked t-waves in Roman
then we’re only two and we don’t see that and also here in v1 we look for a
large upward deflection and a small downward deflection that would be right
atrial enlargement and we don’t see that here the other thing that you’d see for
left atrial enlargement is a small positive and a large negative deflection
in the P wave if we don’t see that either so we don’t see any evidence for
right atrial or left atrial enlargement what about right ventricular hypertrophy
so right ventricular I have purchased you to look back at lead v1 and you’re
going to be looking for an R wave that’s bigger than an S wave clearly here the S
wave is bigger so there’s no evidence of right ventricular hypertrophy let’s look
at left ventricular hypertrophy and the criteria for that is the number of
millimeters here it’s the S wave in lead v1 and here you can see that we’re
talking about oh I don’t know about six or seven okay we’re going to come back
to that later because we’re not done with that number six and I’ll show you
why it’s a little tricky and then we’re looking in lead v5 specifically for a R
wave and the R wave here is what five 10 probably 12 millimeters so 12
millimeters however remember don’t get fooled it’s 20 millimeters per Mille
volt we’re actually really adding a millivolt so we really since worked
we’re since we’re stretching this out with this calibration we really need to
add this up and divide it by two so that would be 18 divided by 2 is 9 so this is
essentially 9 millivolts total is the S wave and v1 and the R wave in v6 and so
9 millimeters is far short of the 35 millimeter criteria for left ventricular
hypertrophy so we don’t see any any of the 4 chamber enlargement we don’t see
right atrial enlargement left atrial enlargement right ventricular
hypertrophy or left ventricular hypertrophy so we can check that off the
next and last thing we go to here is ST segments and I think that’s really where
the key is for those of you who have kind of looked ahead on this we’re
seeing big time ST segment elevation here in 2
we’re also seeing it in v2 we’re seeing it in v3 we’re seeing it in v4 we’re
seeing it in v5 we’re seeing it in v6 also in lead 3 we’re seeing a bit of it
in lead AVF as well but not to the same degree we’re seeing it all over the
place it’s not in any one particular distribution so you’ve got to be careful
because when you see global ST segment elevation all throughout the leads the
one big thing that you’ve got to think about in this situation is definitely
pericarditis pericarditis is an important diagnosis to make because it’s
very close cousin alternative diagnostically on the EKG is a
myocardial infarction now in some of these centres that can’t do angiography
within 90 minutes they have to give TPA you don’t want to give TPA to some with
pericarditis because if you’ve got bleeding into the pericardium that can
very quickly turn into tamponade which is obviously life-threatening and so you
want to give TPA to those that you think have an inclusion in the coronary artery
and you definitely do not want to give TPA to someone pericarditis both of
those will have ST segment elevation one will be global
as in pericarditis the other one will be segmental either 2/3 a VF or inferior or
it will be v1 v2 for an anterior or will be V for five and six for a lateral okay
so I think what we’ve got here is pericarditis with a heart rate of 138
sinus / atrial fibrillation with a mild left axis deviation and no signs of
hypertrophy and that is the EKG join us for more EKGs to go over as you know his
practice makes perfect thanks for joining us
you


5 thoughts on “ECG Interpretation Practice – Pericarditis on EKG Explained!

  1. Interpret ECGs with confidence – join Dr. Seheult for the complete ECG Clarity video series available at https://www.medcram.com/courses/ekg-ecg-interpretation-explained-clearly

  2. I love your videos. If you haven't already, could you please do a video on lymphorrhea? The various types, causes and treatment. Thank you.

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