hey Mark what's going on hey dr. Kafka
I'm just looking at this EKG I'm a new
patient I admit it I think they're
having an acute MI and I'm pretty sure
there's ST elevation what do you think
well let me take a look
you know I am worried about acute
myocardial infarction in this patient
let me call the cath lab and then we'll
discuss the ECG findings a little
further great
st-elevation myocardial infarction or a
STEMI is basically the complete
occlusion of a quarter ii artery in the
heart and rapid identification of this
can literally save your patients heart
muscle or their life now let's take a
look at this on the form of an EKG and
the EKG here we're gonna be looking for
one millimeter or more ST elevation and
two or more consecutive leads hey doctor
chemica where should we be looking on
the ST segment for the elevated portion
that's a great question mark so we're
looking for something called the J point
which is right here
now the J point is at the end of the QRS
segment and at the onset of the ST
segment okay and what are we comparing
the J point to so if the J point is here
we're gonna compare the PR segment as
our baseline which is right here okay so
one millimeter or more of St elevation
at the J point compared to the PR
segment does the shape of the ST segment
matter at all that's actually extremely
important so you have many different
reasons to have st elevations some
examples are early repolarization left
ventricular hypertrophy or pericarditis
so how do we know that we're having
acute occlusion of a coronary artery so
one if I'm looking at the normal end of
the J point right here and if it's
rising over one millimeter and it's
either horizontally going across or if
it's merging with the T wave and forming
a convex or Tombstone finding that's
more concerning for an ST elevation
myocardial infarction okay so if that's
convex that means that this one in front
of me is concave and this would be less
concerning for an MI you got it but
always remember to fight clinically
correlate these findings okay I think I
understand that's the elevation a little
better let's talk about consecutive
leads
hey dr. Kafka I heard you talking on
rounds the other day about consecutive
leads what are those and why are they
important well first of all I'm
impressed that you were actually
listening on rounds
that's a first consecutive leads or
contiguous leads are an ECGs version of
the anatomic portions of the heart okay
and I heard you mentioned before that we
need two or more consecutively it's
involved or an acute MI exactly we're
trying to take a look at a snapshot of
something in two different leads or two
different camera viewpoints okay so if
we had an inferior infarct which leads
would be involved so that would be two
three and ABF okay what about lateral
infarct lateral in parks r1 AVL v5 and
v6 okay and what about anterior septal
Anto septal is going to be v1 and v2
okay and lastly what about interior
apical answer or apical in parks are
going to be v3 and v4 okay I think I
understand consecutive leads a little
bit better let's talk about reciprocal
changes okay now that we understand
consecutive leads a little bit better
let's talk about the term reciprocal
changes so what does that mean and why
is that important so reciprocal changes
are basically looking at the ECG on the
opposite side from where you're having
the current of injury and they're
usually in the form of an ST depression
okay so if we had an anterior ST
elevation mi we would expect a posterior
change logically that makes sense but
remember your heart is irregularly
shaped so when we're talking about
anterior ST elevation we're actually
looking at the inferior portion for ST
depressions okay and likewise if you had
an inferior mi you would expect changes
anteriorly that's correct so if you're
having ST elevations and leads to three
and a VF you're actually gonna be
looking anteriorly for ST depressions
and leads v1 all the way up to possibly
v4 oh okay
and what about if you had an ST
elevation in the lateral wall so the
lateral wall is a little challenging
there in your standard 12-lead ECG
there's no great opposite side okay
I think our patient earlier must have
had an anterior STEMI how did she do
she's actually doing really well they
were able to open up her corners and
she's recovering in the CCU
great thank goodness we knew how to read
EKGs as well