EKGs: How do I know if it’s
good enough? Phlebotomy 2016
Objectives
Understand basic functioning of the heart
Understand the purpose of 12-lead EKGs
Demonstrate correct lead placement for
obtaining quality 12-lead EKGs
Recognize baseline wander and artifact in
an EKG
The Heart
The heart is a big ball of muscle
This muscle pumps deoxygenated (used)
blood returning from the body into the
lungs to get re-oxygenated
It then pumps the oxygenated blood to
the body
The Heart
Because the heart is
made of muscle
electrical signals are
needed to make it
“beat”
These electrical signals
are represented as
lines on an EKG
Each part of the line
represents something
different
12-lead EKGs: What are they for?
You may see patients
on a telemetry
monitor, this is like a
condensed version of a
12-lead
A 12-lead EKG shows
us a 3-D picture of the
electrical activity in the
heart
Allows for specific
diagnosis
12-lead EKGs
Lets look at a typical 12-lead print out
It may look like a bunch of squiggly lines
all running together
But in fact, it is the 12 different pictures of
the heart’s conduction
Includes some large pictures of major
leads at the bottom
%
Lead Placement
Where you place the leads during an EKG is very important
If it is off as much as a centimeter it can cause major deviation
Sometimes incorrect lead placement can mimic serious heart disease
Lead Placement
What’s wrong with these
placements? V3 is incorrectly placed
What’s wrong with these
placements? V4, V5 and V6 should be in a straight line
What’s wrong with these
placements? V1 and V2 are too far apart
V3 should be at a diagonal between V2 and V4
A few pointers about placement
If your patient is hairy, shave them!
If your patient is wet, dry them!
Do not apply leads over breast tissue
Limb leads can go on limbs or torso
Do not place leads over pacemakers or central
line ports
How to know when an EKG is good
enough to capture: “I’ve got the green light/all three dots are
full, that means it’s good—right?”
WRONG!
Sometimes the machine thinks it is a
quality EKG when in fact it’s not
Need to use your own judgment skills
Does this mean I’m reading the
EKG?! NO! You are not responsible for
reading or interpreting the EKG
There are two major things to look for
before you capture an EKG, and they have
nothing to do with interpreting or reading
the EKG itself
◦ Baseline
◦ Artifact
Major Points—Baseline
What is baseline?
◦ Baseline means that all the EKG leads follow a
straight line—after the up and down
deflections there is still a nice even line across
the page
◦ Ignore everything but the big picture
Major Points—Baseline
Can be affected by
◦ Poor lead placement
◦ Heavy breathing
◦ Agitated or uncomfortable patient
Major Points-Artifact
What is artifact?
◦ We’ve already discussed that EKGs read
electrical signals that you heart gives off as it
beats
◦ But it’s not just the heart that gives off these
signals—all other muscles in your body do
◦ When someone is not lying still during an
EKG all the extra muscle movement shows up
as “noise” on the EKG, also known as artifact
Quality EKG—No Artifact
Poor EKG—Lots of Artifact
How can I tell the difference
between artifact and the EKG?
Sometimes it can be hard to tell
◦ If you are ever not sure, ask!
Tips:
◦ Look at the rest of the EKG—does it all look fairly similar?
◦ Are there a bunch of up and down lines all bunched together? That’s artifact.
◦ Make sure your patient is holding as still as possible
◦ Ensure no one else is touching the patient or the bed
◦ Keep lead wires neat and uncrossed
◦ Lay your patient as flat as possible
Preventing Artifact and Baseline
Wander Try and lay the patient as flat as possible
◦ Patient condition permitting
Explain to the patient that they should
remain as still as possible, and that the
test doesn’t take long
Ensure all extremities are relaxed
Sometimes patients with muscle tremors
have artifact and it can’t be helped
PRACTICE!
Disclaimer***
It is understood that
the patient’s
condition may not
permit for a high
quality EKG right
away
◦ i.e. in severe pain,
seizures, respiratory
distress etc.
Do the best you can
However, if a quality
EKG cannot be
obtained initially, it
should be repeated
once the patient is
stabilized
Review
You are not responsible for reading
or interpreting the EKG in any way
Your responsibility is to get a high quality
EKG tracing ensuring correct lead
placement and clear capture
Reference
Dubin, D. (2000). Rapid Interpretation of
EKG's (6th ed.). Ft. Myers, FL: Cover
Publishing Company.