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

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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.