1. APPLICATION FOR THE ECG EVALUATING THE ECG
MAKING ECG’S EASY
APPLICATION FOR THE ECG
EVALUATING THE ECG

2. Upon completion one will be able to:
Describe what an ECG is.
Describe the proper hook-up procedure for a 12-Lead ECG
Identify basic normal ECG waveform morphology.
Distinguish between basic ECG arrhythmia and artifact.

3. QUICK REVIEW OF HEART Purpose Pumps blood Basic Anatomy 4 chambers
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QUICK REVIEW OF HEART
Purpose
Pumps blood
Basic Anatomy
4 chambers
2 sides
4 valves
In an adult with a healthy heart, the heart rate is usually about 72 beats per minute.
The excitatory and electrical conduction system of the heart is responsible for the contraction and relaxation of the heart muscle.
The heart is divided into four chambers, but it functions as a two sided pump.
Top is the right and left atria
Bottom is the right and left ventricles
The right side of the heart receives and pumps venous blood to the lungs.
The left side of the heart receives (from the lungs) and pumps arterial blood to the body.

4. THE CONDUCTINGY SYSTEM
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THE CONDUCTINGY SYSTEM
SA Node
Inter-nodal pathway
AV Node
Bundle of HIS
Bundle Branches
Purkinje Fibers
The sinoatrial node (SA node) is the pacemaker where the electrical impulse is generated. This node is located along the posterior wall of the right atrium right beneath the opening of the superior vena cava. It is crescent shaped and about 3 mm wide and 1 cm long.
The impulse travels from the SA node through the internodal pathways to the atrioventricular node (AV node).
The AV node is responsible for conduction of the impulse from the atria to the ventricles. The impulse is delayed slightly at this point to allow complete emptying of the atria before the ventricles contract. The impulse continues through the AV bundle and down the left and right bundle branches of the Purkinje fibers.
The Purkinje fibers conduct the impulse to all parts of the ventricles, causing contraction (Guyton, 1982).

5. RELATIONSHIP MAKING ECGS EASY - CDOCKX
Lets look at how the conduction system related to what we record on the ECG.
P wave: the sequential activation (depolarization) of the right and left atria
QRS complex: right and left ventricular depolarization (normally the ventricles are activated simultaneously)
ST-T wave ventricular repolarization
U wave: origin for this wave is not clear - but probably represents "afterdepolarizations" in the ventricles   PR interval: time interval from onset of atrial depolarization (P wave) to onset of ventricular depolarization (QRS complex) QRS duration: duration of ventricular muscle depolarization QT interval: duration of ventricular depolarization and repolarization RR interval: duration of ventricular cardiac cycle (an indicator of ventricular rate) PP interval: duration of atrial cycle (an indicator of atrial rate)

6. CARDIAC CYCLES MAKING ECGS EASY - CDOCKX Recorded on graph paper.
Time is measured across
Voltage is measured up and down.
Small squares 1mm high 0.04 secs wide
5 small squares = 1 large square
1 large square is 5mm high and 0.20 sec wide

7. 12 LEAD ECG Learning objectives: Describe the correct
placement of all electrodes
Proper Skin preparation
Care of the ECG machine, wires and electrodes

8. Principles of Electrocardiograph
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Principles of Electrocardiograph
Electrocardiograph – is the instrument that records the electrical activity of the heart
Electrocardiogram (ECG) is the record of that activity

9. HOOKING UP THE 12-LEAD ECG
Proper skin prep
Placement of the limb electrodes
Placement of the chest electrodes

10. SKIN PREPARATION REASON FOR SKIN PREPARATION 5 STEP METHOD
MAKING ECGS EASY - CDOCKX
SKIN PREPARATION
REASON FOR SKIN PREPARATION
5 STEP METHOD
2 STEP METHOD
Both re-usable and disposable electrodes rely on the electrolyte in the electrodes to
make an effective connection between the machines electrode and the patient’s
electro-physiological signals.
These signals are not picked up just off the surface of the skin,
where dead or dry skin, oils and hair all prevent the signals from being detected.
The signals are under this surface, and thus we have to prepare the patient so that
the electrolyte can reach the signals beneath.
This is achieved by:
Removing oil, greasy and dirt from the skins sites with alcohol

11. ELECTRODE PLACEMENT LIMB LEADS CHEST LEAD MAKING ECGS EASY - CDOCKX
The standard 12-Lead ECG is a collect of tracings of electrical activity occurring in the heart. Each lead provides a tracing, which is characteristic of a different view of the same electrical activity. Other words we take 12 different angles (pictures) of the same activity.
In a standard 12-lead ECG there are 6 limb leads with a three-electrode connection made to the Right arm, Left arm and Left leg. The right leg is also hooked up to the machine but this is your ground lead and does not generate a signal on the ECG.

12. LIMB LEADS
Bipolar leads
I II III
Augment leads
Avr Avl Avf

13. CHEST LEADS 6 UNIPOLAR LEADS V1 V2 V3 V4 V5 V6
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CHEST LEADS
6 UNIPOLAR LEADS V1 V2 V3 V4 V5 V6
The chest electrodes are labelled “V” and are numbered from 1 to 6.
The placement of these electrodes needs to be exact to give the optimum information as possible. If the electrodes are placed incorrectly on the chest, the tracing will reveal duplication of some information, while other areas will not be represented properly.
Incorrect placement of the electrodes can lead to serious errors of interpretation.
 There are six chest leads: V1, V2,V3,V4, V5 and V6.
V1 at the fourth intercostal space, at the right margin of the sternum
V2 at the fourth intercostal space, at the left margin of the sternum
V3 midway between the position of leads V2 and V4 (in a straight line)
V4 at the fifth intercostals space at the junction of the left midclavicular line
V5 midway between the position of leads V4 and V6 (straight down from the axillary
Line on the same horizontal position as V4 and V6
V6 at the horizontal position of V4, at the left of the midaxillary line.

14. LETS REVIEW What is an ECG What are the limb leads?
What are the chest leads?
Why do skin prep?

15. 12-LEAD ECG LAYOUT

16. INFORMATION ON THE ECG Patients demographics
Heart rate and measurements
Speed ECG is recorded at
Voltage ECG is recorded at
What the filter is set on

17. INFORMATION ON THE 12-LEAD ECG

18. WHAT YOU NEED TO LOOK FOR
Are the limb leads hooked up correctly?
Are the chest leads hooked up correctly?
Is the ECG free of artifact.
Is this ECG a Critical Value

19. IS the ECG HOOKED UP CORRECTLY?
LIMB LEADS
Normal 12-lead
AVR – always negative
Lead I – always positive
Lead II, III – positive or biphasic
CHEST LEADS
COLUMN III
R wave progression
Small to Tall
COLUMN IV
Tall to Small

20. RULING OUT LIMB LEAD REVERSAL
Avr is always negative
Lead I is always positive
Lead II and III positive for the P wave and usually the QRS complex

21. CHEST LEADS CHEST LEADS COLUMN III R wave progression Small to Tall
COLUMN IV
Tall to Small

22. LIMB LEADS MAKING ECGS EASY - CDOCKX
Lets look at this ECG for the limb leads?
Is lead I positive? Is AVR negative
We have reversed our limb electrodes we have the right arm on the left arm and reverse.

23. CHEST LEADS MAKING ECGS EASY - CDOCKX
We need to have R wave progression
In column III the R wave(first positive wave of the QRS) goes from short to tall V1 shortest R wave
V2 R wave taller than in V1 and V3 has the tallest R wave.
In column IV the R wave is always the shortest in V6.

25. MAKING ECGS EASY - CDOCKX
Is this ECG hooked up correctly for the limb leads?
Is it for the chest leads?

26. MAKING ECGS EASY - CDOCKX
Lets evaluate this ECG to see if the Limb leads and Chest Leads are hooked up correctly?

27. MAKING ECGS EASY - CDOCKX
Is this ECG HOOKED UP CORRECTLY FOR LIMB AND CHEST?

28. OTHER PROBLEMS WITH THE ECG
Artifact
Electrical interference
Somatic tremor
Wandering baseline

29. EINTHOVENS TRIANGLE MAKING ECGS EASY - CDOCKX
Lead I = right arm and left arm
Lead II = right arm and left Leg
Lead III = left arm and Left Leg.

30. ARTIFACT ON THE ECG

31. FIND THE ARTEFACT

32. WANDERIN BASELINE

33. SOMATIC TREMOR

34. ELECTRICAL INTERFERANCE

35. BASIC CRITICAL VALUES Bradycardia – HR < 40bpm
Tachycardia HR > 120bpm
PVC’s - 4 or more in a row
ST Elevation

36. LOOKING AT THE RHYTHM
Evaluate the rhythm strip at the bottom of the 12-lead for the following
Is the rhythm regular or irregular?
Is there a P wave before every QRS complex
Are they any abnormal beats.

37. FINDING THE HEART RATE
3 METHODS
RATE RULER
COUNTING
BOX METHOD

38. BOX METHOD MAKING ECGS EASY - CDOCKX
Look at the number of large boxes before two R waves and then using this method find the HR .
I just remember that 2 ½ large boxes or less is critical value for tachycardia
7 or more large boxes is critical for bradycardia

39. MAKING ECGS EASY - CDOCKX
Look at the rhythm strip is it regular or irregular.
How many large boxes are between two R waves = 5 = 60bpm

40. MAKING ECGS EASY - CDOCKX
Is the rhythm regular? What is the heart rate?

43. ECTOPIC BEATS

44. ECTOPIC BEATS

45. LETS SUMMARIZE How do we produce an excellent 12-lead ECG?
Proper skin prep
Correct electrode placement
Recognize and know how to correct problems
Recognize basic critical values