This document provides instructions for performing an electrocardiogram (ECG). It begins with an overview of ECG technology and the 12 leads recorded. It describes how to place the 10 electrodes on the patient's chest, arms, and legs in standard positions. The document provides guidance on preparing the patient, attaching the color-coded cables to the correct electrodes, and using the ECG machine to record the traces from the 12 leads. The goal is to educate medical practitioners on properly conducting an ECG to interpret the electrical activity and rhythms of the heart.

1. TECHNICAL SKILLSTECHNICAL SKILLS
HOW TO DOHOW TO DO
AN ECGAN ECG
Dr D Byrne 2015
References available on requestReferences available on request
TECHNICAL SKILLSTECHNICAL SKILLS
HOW TO DOHOW TO DO
AN ECGAN ECG
Dr D Byrne 2015
References available on requestReferences available on request

2. PLEASE VIEW THEPLEASE VIEW THE
TUTORIAL IN SLIDE SHOWTUTORIAL IN SLIDE SHOW
FORMATFORMAT
PLEASE VIEW THEPLEASE VIEW THE
TUTORIAL IN SLIDE SHOWTUTORIAL IN SLIDE SHOW
FORMATFORMAT

3. LEARNING OBJECTIVESLEARNING OBJECTIVESLEARNING OBJECTIVESLEARNING OBJECTIVES
At the end of this tutorial you should be able to:At the end of this tutorial you should be able to:
1. Use the ECG machine1. Use the ECG machine
2.2. Perform an ECGPerform an ECG
3. Interpret an ECG in a systematic manner3. Interpret an ECG in a systematic manner

4. TUTORIAL OUTLINETUTORIAL OUTLINETUTORIAL OUTLINETUTORIAL OUTLINE
Understanding the ECGUnderstanding the ECGUnderstanding the ECGUnderstanding the ECG
Indications and usesIndications and usesIndications and usesIndications and uses
How to do an ECGHow to do an ECGHow to do an ECGHow to do an ECG
FAQsFAQsFAQsFAQs
System for easy interpretation of the ECGSystem for easy interpretation of the ECGSystem for easy interpretation of the ECGSystem for easy interpretation of the ECG

5. UNDERSTANDING THEUNDERSTANDING THE
ELECTROCARDIOGROMELECTROCARDIOGROM
(ECG or EKG)(ECG or EKG)
UNDERSTANDING THEUNDERSTANDING THE
ELECTROCARDIOGROMELECTROCARDIOGROM
(ECG or EKG)(ECG or EKG)
Introduction:Introduction: The ECG is aThe ECG is a
transthoracic interpretation of thetransthoracic interpretation of the
electrical activity of the heartelectrical activity of the heart
captured over time and externallycaptured over time and externally
recorded by skin electrodes.recorded by skin electrodes. It is theIt is the
best way to measure and diagnosebest way to measure and diagnose
abnormal rhythms of the heart andabnormal rhythms of the heart and
to diagnose if heart muscle hasto diagnose if heart muscle has
been damaged in specific areasbeen damaged in specific areas
during a myocardial infarction (MI).during a myocardial infarction (MI).

6. UNDERSTANDING THE ECGUNDERSTANDING THE ECG
‘‘LEADS’LEADS’
UNDERSTANDING THE ECGUNDERSTANDING THE ECG
‘‘LEADS’LEADS’
A 12 lead ECG is one in which 12 different electricalA 12 lead ECG is one in which 12 different electrical
signals are recorded at approximately the same timesignals are recorded at approximately the same time
and is typically printed out onto paper.and is typically printed out onto paper.
There are 10 electrodes in a 12 lead ECG.There are 10 electrodes in a 12 lead ECG.
The electrodes are combined into pairs and the outputThe electrodes are combined into pairs and the output
form each pair is known as a LEAD.form each pair is known as a LEAD.
The tracing of the voltage difference between 2 of theThe tracing of the voltage difference between 2 of the
electrodes, as produced by the ECG recorder, is whatelectrodes, as produced by the ECG recorder, is what
the term LEAD refers to and each will have a specificthe term LEAD refers to and each will have a specific
name e.g. Lead 1 is the voltage difference between thename e.g. Lead 1 is the voltage difference between the
right arm electrode and the left arm electroderight arm electrode and the left arm electrode..
A 12 lead ECG is one in which 12 different electricalA 12 lead ECG is one in which 12 different electrical
signals are recorded at approximately the same timesignals are recorded at approximately the same time
and is typically printed out onto paper.and is typically printed out onto paper.
There are 10 electrodes in a 12 lead ECG.There are 10 electrodes in a 12 lead ECG.
The electrodes are combined into pairs and the outputThe electrodes are combined into pairs and the output
form each pair is known as a LEAD.form each pair is known as a LEAD.
The tracing of the voltage difference between 2 of theThe tracing of the voltage difference between 2 of the
electrodes, as produced by the ECG recorder, is whatelectrodes, as produced by the ECG recorder, is what
the term LEAD refers to and each will have a specificthe term LEAD refers to and each will have a specific
name e.g. Lead 1 is the voltage difference between thename e.g. Lead 1 is the voltage difference between the
right arm electrode and the left arm electroderight arm electrode and the left arm electrode..

7. UNDERSTANDING THE ECGUNDERSTANDING THE ECG
‘‘GRAPH PAPER’GRAPH PAPER’
UNDERSTANDING THE ECGUNDERSTANDING THE ECG
‘‘GRAPH PAPER’GRAPH PAPER’
An ECG machine will print onto graph paper which hasAn ECG machine will print onto graph paper which has
a background pattern of 1mm squares in red or greena background pattern of 1mm squares in red or green
with bold divisions every 5mm in both horizontal andwith bold divisions every 5mm in both horizontal and
vertical directionsvertical directions.. One small block on ECG paperOne small block on ECG paper
translates into 40ms and one large block (5 smalltranslates into 40ms and one large block (5 small
blocks) translates into 200ms.blocks) translates into 200ms.
An ECG machine will print onto graph paper which hasAn ECG machine will print onto graph paper which has
a background pattern of 1mm squares in red or greena background pattern of 1mm squares in red or green
with bold divisions every 5mm in both horizontal andwith bold divisions every 5mm in both horizontal and
vertical directionsvertical directions.. One small block on ECG paperOne small block on ECG paper
translates into 40ms and one large block (5 smalltranslates into 40ms and one large block (5 small
blocks) translates into 200ms.blocks) translates into 200ms.

8. UNDERSTANDING THE ECGUNDERSTANDING THE ECG
‘‘LAYOUT’LAYOUT’
UNDERSTANDING THE ECGUNDERSTANDING THE ECG
‘‘LAYOUT’LAYOUT’
The 12 lead ECG will show a short segment of theThe 12 lead ECG will show a short segment of the
recording of each of the 12 leads.recording of each of the 12 leads.
This is arranged into 4 columns, each containing 3 rows.This is arranged into 4 columns, each containing 3 rows.
• First Column:First Column: Limb leads (I, II, III)Limb leads (I, II, III)
• Second Column:Second Column: Augmented limb leads (aVR, aVL, aVF)Augmented limb leads (aVR, aVL, aVF)
• Third and Fourth Column:Third and Fourth Column: Chest leads (V1 – 3, V4 – 6)Chest leads (V1 – 3, V4 – 6)
To help analysis a rhythm strip is also recorded whichTo help analysis a rhythm strip is also recorded which
shows the rhythm for the whole time the ECG wasshows the rhythm for the whole time the ECG was
recorded (5 or 6 seconds).recorded (5 or 6 seconds).
The 12 lead ECG will show a short segment of theThe 12 lead ECG will show a short segment of the
recording of each of the 12 leads.recording of each of the 12 leads.
This is arranged into 4 columns, each containing 3 rows.This is arranged into 4 columns, each containing 3 rows.
• First Column:First Column: Limb leads (I, II, III)Limb leads (I, II, III)
• Second Column:Second Column: Augmented limb leads (aVR, aVL, aVF)Augmented limb leads (aVR, aVL, aVF)
• Third and Fourth Column:Third and Fourth Column: Chest leads (V1 – 3, V4 – 6)Chest leads (V1 – 3, V4 – 6)
To help analysis a rhythm strip is also recorded whichTo help analysis a rhythm strip is also recorded which
shows the rhythm for the whole time the ECG wasshows the rhythm for the whole time the ECG was
recorded (5 or 6 seconds).recorded (5 or 6 seconds).

9. INDICATIONS AND USESINDICATIONS AND USESINDICATIONS AND USESINDICATIONS AND USES
Cardiac murmersCardiac murmers
Syncope or collapseSyncope or collapse
SeizuresSeizures
Perceived cardiac dysrhythmiasPerceived cardiac dysrhythmias
Symptoms of myocardial infarctionSymptoms of myocardial infarction
Suspected pulmonary embolusSuspected pulmonary embolus
The assessment of patients with systemic diseaseThe assessment of patients with systemic disease
The pre operative assessment of patientsThe pre operative assessment of patients
Monitoring during anaesthesia and critically ill patientsMonitoring during anaesthesia and critically ill patients

10. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
Review the indications for the ECGReview the indications for the ECG.
Preparation:Preparation:
Practice hand hygiene and introduce yourself to the patientPractice hand hygiene and introduce yourself to the patient

11. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
Say:Say:
“Hello Mr. Smith, My name is Dr. O Brien
and I would like to carry out a simple test
on your heart. It is called an
electrocardiogram or an ECG. It is a
recording of your heart’s activity. The
reason for this test is……. It is painless. I will
have to put stickers onto your chest, arms
and legs. I will attach wires to these
stickers and the ECG machine will print out
a reading onto a piece of paper. I will ask
you to sit up in the bed so that you are
comfortable and to remove your top.
Please ask me any questions that you may
have”.

12. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
Electrode (dot) Placement:Electrode (dot) Placement:
The electrodes consist of a conducting gel embedded in theThe electrodes consist of a conducting gel embedded in the
middle of a self adhesive pad to which the wires clip.middle of a self adhesive pad to which the wires clip.
Ensure that the chest is dry and if the patient is very hairy,Ensure that the chest is dry and if the patient is very hairy,
you may have to shave the area where the electrodes will beyou may have to shave the area where the electrodes will be
placed.placed.
Practice Hand HygienePractice Hand Hygiene
Open a packet of electrodes.Open a packet of electrodes. Peel off the backing from eachPeel off the backing from each
electrode and place as follows:electrode and place as follows:

13. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
The Six Chest Electrodes:The Six Chest Electrodes:
The electrodes for the chest leads MUST go in the standard positionsThe electrodes for the chest leads MUST go in the standard positions
V1 - Fourth intercostal space,V1 - Fourth intercostal space,
right sternal borderright sternal border
Fourth intercostal
space
Right sternal
border

14. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
The Six Chest Electrodes :The Six Chest Electrodes :
The electrodes for the chest leads MUST go in the standard positionsThe electrodes for the chest leads MUST go in the standard positions
V2 - Fourth intercostal space,left sternal border.V2 - Fourth intercostal space,left sternal border.
Fourth
intercostal
space,left
sternal border.

15. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
The Six Chest Electrodes:The Six Chest Electrodes:
The electrodes for the chest leads MUST go in the standard positionsThe electrodes for the chest leads MUST go in the standard positions
V4 - Fifth intercostal space, left midclavicular line.V4 - Fifth intercostal space, left midclavicular line.
V4 - Fifth
intercostal
space
Left
midclavicular
line

16. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
The Six Chest Electrodes:The Six Chest Electrodes:
The electrodes for the chest leads MUST go in the standard positionsThe electrodes for the chest leads MUST go in the standard positions
V3 - Midway between V2 and V4V3 - Midway between V2 and V4
V3 - Midway
between
V2 and V4

17. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
The Six Chest Electrodes:The Six Chest Electrodes:
The electrodes for the chest leads MUST go in the standard positionsThe electrodes for the chest leads MUST go in the standard positions
V6 - Level with V4, left mid axillary line.V6 - Level with V4, left mid axillary line.
V6 - Level
with V4, left
mid axillary
line.

18. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
The Six Chest Electrodes:The Six Chest Electrodes:
The electrodes for the chest leads MUST go in the standard positionsThe electrodes for the chest leads MUST go in the standard positions
V5 - Level with V4, left anterior axillary line.V5 - Level with V4, left anterior axillary line.
V5 - Level
with V4, left
anterior
axillary line.

19. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
The Limb Electrodes:The Limb Electrodes:
These can be placed along the arms and legs at any point providedThese can be placed along the arms and legs at any point provided
they are below the shoulder in the upper limb and below the inguinalthey are below the shoulder in the upper limb and below the inguinal
fold in the lower limbs. In the case of recording serial data, consistencyfold in the lower limbs. In the case of recording serial data, consistency
for the limb lead placement is important.for the limb lead placement is important.

20. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
The 10 electrodes :The 10 electrodes :

21. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
Attach The Cables:Attach The Cables:
Untangle the cables before clipping them onto the electrodesUntangle the cables before clipping them onto the electrodes
Attach the appropriate cables to the dots by opening theAttach the appropriate cables to the dots by opening the
crocodile jaws and grasping the metal button on the electrodecrocodile jaws and grasping the metal button on the electrode
Try to avoid crossing wiresTry to avoid crossing wires

22. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
Cable Colours And Chest Electrodes To Which They Attach:Cable Colours And Chest Electrodes To Which They Attach:
White/Red –White/Red –
C1/V1.C1/V1.

23. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
Cable Colours And Chest Electrodes To Which They Attach:Cable Colours And Chest Electrodes To Which They Attach:
White/Yellow – C2/V2White/Yellow – C2/V2

24. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
Cable Colours And Chest Electrodes To Which They Attach:Cable Colours And Chest Electrodes To Which They Attach:
White/Green – C3/V3.White/Green – C3/V3.

25. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
Cable Colours And Chest Electrodes To Which They Attach:Cable Colours And Chest Electrodes To Which They Attach:
White/Brown – C4/V4.White/Brown – C4/V4.

26. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
Cable Colours And Chest Electrodes To Which They Attach:Cable Colours And Chest Electrodes To Which They Attach:
White/Black – C5/V5.White/Black – C5/V5.

27. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
Cable Colours And Chest Electrodes To Which They Attach:Cable Colours And Chest Electrodes To Which They Attach:
White/Violet – C6/V6.White/Violet – C6/V6.

28. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
Limb Cables: RememberLimb Cables: Remember
RRed Fored For RRight Arm.ight Arm.
YYellow for Left Armellow for Left Arm
(Think of(Think of Lemon Yellow/LeftLemon Yellow/Left).).
BBlack andlack and GGreenreen
Are Lower Limb Leads.Are Lower Limb Leads.
((ThinkThink EarthEarth andand GrassGrass Colours).Colours).

29. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
The 10 CablesThe 10 Cables

30. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
Turn on the machineTurn on the machine
Check that paper insertedCheck that paper inserted
Insert the patientInsert the patient’s details into the machine’s details into the machine
Press the record buttonPress the record button
Review the ECG and ensure that all 12 leadsReview the ECG and ensure that all 12 leads
and rhythm strip are recordedand rhythm strip are recorded
Tear off ECG and check patientTear off ECG and check patient’s name, medical’s name, medical
record number, date and time.record number, date and time.
Write symptoms at time of recording on the tracingWrite symptoms at time of recording on the tracing
e.g. chest pain….e.g. chest pain….

31. HOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECGHOW TO DO AN ECG
Turn off the machineTurn off the machine
Remove the cablesRemove the cables
Remove the electrodes (dots)Remove the electrodes (dots)
and dispose in clinical wasteand dispose in clinical waste
Practice hand hygienePractice hand hygiene
Thank the patientThank the patient
Document date, time, indication and findingsDocument date, time, indication and findings
in the patientin the patient’s notes’s notes

32. FAQsFAQsFAQsFAQs
Q.Q. The patient has a very hairy chest and the electrodes (dots) will not stick.The patient has a very hairy chest and the electrodes (dots) will not stick.
Ans: Shave the chest in the areas for electrode placement.
Q.Q. The patient has a lot of piercings, including nipple piercings.The patient has a lot of piercings, including nipple piercings.
Will I remove them?Will I remove them?
Ans: No. Be sure not to put an electrode (dot) over the piercing though.
Just work around them.

33. FAQsFAQsFAQsFAQs
Q.Q. The patient is a female. Can I place the electrodes on her breasts?The patient is a female. Can I place the electrodes on her breasts?
Ans: No. Place the electrodes on the chest wall by lifting up the breast.
Q.Q. The patient is a lady. Can she leave her bra on?The patient is a lady. Can she leave her bra on?
Ans: No. Place the electrodes on the chest wall by lifting up the breast.
Q.Q. The tracing is very shaky or parts of it are missing.The tracing is very shaky or parts of it are missing.
Ans: Ensure the patient stays still during the recording and check that all
electrodes are in good contact with the skin. If the skin is damp, they will not
stick.

34. ECG Interpretation: A SystematicECG Interpretation: A Systematic
ApproachApproach
ECG Interpretation: A SystematicECG Interpretation: A Systematic
ApproachApproach
We Recommend YouWe Recommend You
Download a Copy of WithamDownload a Copy of Witham
‘‘ECG interpretation’ at ThisECG interpretation’ at This
Web Address:Web Address:
http://sichon.wu.ac.th/file/pt-shh-20110612-135010-XwBq1.pdf

35. Thank youThank you
We hope that you enjoyed theWe hope that you enjoyed the
presentation.presentation.
Thanks to the interns in Network WestThanks to the interns in Network West
Northwest for their help andNorthwest for their help and
enthusiasm.enthusiasm.