12 and 15 Lead Acquisition
STEMI Recognition Class
12 Lead Rapid Acquisition
• Module 1 Electrode Location
• Module 2 Electrode Placement
• Module 3 How to do a 15 Lead
• Module 4 Demonstrations
• Module 5 Reducing Artifact
• Module 6 Tips and Techniques
Module 1 Electrode Location
Electrodes must be placed in the
proper position to obtain an
accurate 12 Lead ECG
Module 1 Electrode Location
12 leads obtained from 10 electrodes
• 4 on the limbs
• 6 on the chest
Module 1 Electrode Location
Limb lead positioning is simple.
The electrodes are placed off the
torso, on the limbs. The most
correct positioning is near the
wrist and ankles.
However, EMS generally places
the electrodes on/near the torso
to limit artifact while
transporting.
Module 1 Electrode Location
Chest leads have
specific anatomic
locations
V1, V2, V4 the
rest are placed
in relationship
to these leads
Module 1 Electrode Location
Module 1 Electrode Location
Module 1 Electrode Location
Module 1 Electrode Location
Module 1 Electrode Location
Module 1 Electrode Location
Module 1 Electrode Location
Module 1 Electrode Location
Module 2 Electrode Placement
•The key to correctly placing the chest electrodes is
finding the 4th intercostal space
Module 2 Electrode Placement
Module 2 Electrode Placement
Module 2 Electrode Placement
Here’s another approach to locating the 4th intercostal space
Module 2 Electrode Placement
Best view laterally
Module 2 Electrode Placement
• Locate the supersternal notch
(1) at the top of the manubrium
• Palpate down appox 2” until
you find the sternal angle, slide
your finger laterally to the right,
you’re finger is now on the 2nd
rib
•Palpate down into the 2nd 3rd
and 4th intercostal space
Module 2 Electrode Placement
After placing V2, palpated down to the 5th intercostal
space midclavicular line and place V4
Module 2 Electrode Placement
15 Leads are simple
Remove V4 and move it
5th intercostal space,
midclivicular on the Right
side of Pt’s chest
V1
V2
V3
V4R
V4
Module 2 Electrode Placement
15 Leads are simple
Remove V4 and move it
5th intercostal space,
midclavicular on the
Right side of Pt’s chest
Module 2 Electrode Placement
Module 2 Electrode Placement
Module 2 Electrode Placement
Module 2 Electrode Placement
Module 2 Electrode Placement
Module 2 Electrode Placement
Module 2 Electrode Placement
Module 2 Electrode Placement
Module 2 Electrode Placement
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
If you were the patient, where would you prefer to have you’re
12 Lead done, in the house or in the truck?
Module 3 Demonstrations
There’s a lot of people out there and they can see into the
ambulance. You should obtain the 12 lead in the house
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Module 3 Demonstrations
Practice Time
Module 4 Reducing Artifact
Unless you have a clear ECG to analyze, all you interruptive
skills are of little use
Module 4 Reducing Artifact
Stress labs obtain clear
ECG’s while the Patient is
running on a treadmill
We should be able to
obtain a 12 lead while
the Patient is laying
still
Module 4 Reducing Artifact
As the heart depolarizes, an electrode on the Pt’s skin picks
up the electrical activity
Module 4 Reducing Artifact
It can also pick up other electrical signals
Module 4 Reducing Artifact
To reduce artifact, we have to increase the heart’s signal and
reduce the other electrical activity
Module 4 Reducing Artifact
Artifact Reduction Strategy:
Helping the electrode gel to better penetrate the
skin will increase the signal strength from the heart
and reduce the signal strength from other sources.
Module 4 Reducing Artifact
Module 4 Reducing Artifact
Remove hair with electric clippers
Module 4 Reducing Artifact
Module 4 Reducing Artifact
Now the skin is prepared, we can attach our electrodes
Module 4 Reducing Artifact
Module 4 Reducing Artifact
Module 5 Tips and Techniques
Supine is the proper position, if the Pt will tollerate
Module 5 Tips and Techniques
When the Pt changes position, the heart moves within the
chest. This can cause ECG changes similar to a misplaced
electrode.
Module 5 Tips and Techniques
Do your best to maintain the modesty of a female Pt
Module 5 Tips and Techniques
You could try wide medical tape
Module 5 Tips and Techniques
A folded blanket or towel may help hold the electrodes in
place
Module 5 Tips and Techniques
• Strand each lead out individually
• When ECG cables are looped around IV lines, O2
tubing, BP cuff tubing, or dangling between squad bench
and stretcher you will have more artifact
• Make sure the Pt isn’t twiddling the ECG cables
• If unable to lay supine for ECG, place them semifowlers and breathing normally
• Do not allow Pt to prop themselves up by the arms or
you will have muscle tremor artifact
Module 5 Tips and Techniques
• If the Pt is cold/shivering, cover with blanket or sheet
prior to capturing the 12 Lead
Module 5 Tips and Techniques
Same Pt as before, covered with a towel
Module 5 Tips and Techniques
For some Pt’s obtaining a clear ECG will be difficult
(e.g. respiratory distress Pt, sitting up)
However, in most cases it is possible to a 12 Lead ECG
with excellent, or at least acceptable data quality
It just takes effort. A desire to obtain a clean 12 Lead
and the knowledge to trouble shoot problems
Module 5 Tips and Techniques
Myocardial Infarctions are not like broken bones, and
therefore, ECG’s are not like X-rays.
If you’re treating a Pt with a broken hip. That x-ray could
be taken now, 10 min’s from now, an hour from now and
what would you see? A broken hip.
With MI the events in the coronary artery can be changing
moment by moment. The ECG can be very dynamic as well.
There is a value to obtaining repeat ECG’s when you suspect
MI. Making a habit of doing early and repeat ECG’s will help
you identify a STEMI that could easily be missed.
Module 5 Tips and Techniques
Module 5 Tips and Techniques
12 lead Validation
Does Lead I show Global Negativity?
12 lead Validation
Limb Reversal!
12 lead Validation
Look for R Wave Progression in the pre-cordial leads. The QRS
should go from negative to more positive.
Validate this 12 lead
Module 5 Tips and Techniques
This short course provides you with what you need to
know in order to rapidly obtain a 12 Lead ECG that’s both
clear and accurate
Just as the case with ECG interpretation, acquisition also
requires practice. After you’ve done this 20 or 30 times,
you’ll become comfortable and confident
FIN