1. Perform Electrocardiography
HLTPAT407B

2. Objectives Check ECG machine against a checklist before each use
Correctly identify, measure and inform patient regarding the ECG procedure
Record patient information
Position patient for attachment of leads
Attach leads according to procedure manual
Label leads as they are recorded and record if filter is used
Record lead two rhythm strip
Maintain a straight base line
Clean patient’s chest and ECG electrodes
Forward trace to cardiologist
Identify and manage electrical interference
Identify and manage skeletal muscle tremor
Identify and manage wandering baseline

3. definitions
Cardiac cycle is a single rhythmic repetition of the heartbeat
Artifact is the appearance of a false signal which is obviously not from the heart
Arrhythmia is an abnormal heart rhythm
Electrocardiogram a record of the electrical activity of the heart
Waves are deflections from the baseline of the ECG
Electrodes are specially prepared tabs with conductive gel placed on the skin to detect electrical current
Purkinje fibres myocardial cells in the heart that conduct electricity to the ventricles
Sinoatrial node is the pacemaker of the heart
Atrioventricular node cells found in the right atrium
Bundle of His are nerve fibres within the septum

4. What is an ECG?
Provides a record or trace of the electrical activity of the heart
Cardiac muscle tissue generates electrical impulses through the heart
We measure this activity by placing electrodes on the chest wall, arms and legs
Electrical activity show as waveforms named P.Q,R,S and Twaves

5. ECG

6. Cardiac Cycle
Electrical impulse begins in the sino-atrial node in the right atrium

7. Cardiac cycle
The impulse travels along a network of conductive fibres in the atria to the atrioventricular node

8. Cardiac cycle
After a short delay, the impulse passes to the Bundle of His, down the right and left bundle branches, into the purkinje fibres in the ventricles

9. Cardiac cycle
When SA node generates impulse, sodium and calcium move into cells making them contract
This creates a current which flows forward contracting cells next to them
Contraction of the heart occurs-systole

10. Cardiac cycle
potassium leaves the cells and they then relax which returns them to a resting state called diastole
This current also passes to the nearby tissues to the heart
This is why electrodes placed on the skin can detect the current

11. P Wave Represents Atrial contraction
Should be upright, round and symmetrical

12. P Wave High pointed occurs with pulmonary disease
Mitral valve disease can cause wide notch
Absence can mean abnormal impulse generation

13. QRS Represents the contraction of the ventricles
This is a much stronger contraction as it pushes blood out of the ventricles into the arteries
Known as QRS complex

14. T wave Follows QRS and shows that the ventricles have relaxed
Usually upright and is taller and less symmetrical than P wave

15. The rate ECG paper has lines to help count time
3 large squares are equal to 1 sec
To calculate the rate for 1 min, count the number of cycles in any 6 sec interval and multiply by 10

17. The rhythm
Check the atrial rhythm by placing a piece of paper against the P wave and mark with a pencil
Mark the P wave of the next cycle
Move the paper across the tracing and look to see if P wave meets the line you have drawn
P wave should be upright, symmetrical and before the QRS complex

18. QRS complex
Measure from beginning of Q or R wave to the point where the S wave returns to the baseline
Normal time is between 0.5 and 0.10 secs

19. T wave
Should be present, upright and look the same

20. 12 lead ECG A lead records the electrical activity between 2 points
Each lead looks at a small part of the heart
A 12 lead ECG gives a complete picture of this electrical activity
During ECG, some of the electrodes are used twice

21. Lead Placement V1-4th intercostal space at right sternal border
V2-4th intercostal space at left sternal border
V3-midway between 4th and 5th intercostal spaces on left side
V4-5th intercostal space at mid clavicular line
V5- 5th intercostal space anterior axilla
V6-5th intercostal space at midaxillary line

22. Lead placement

23. leads Leads 1,11 and 111 are attached to arms and legs
They measure activity in the front of the heart
Lead 1 measures between LA and RA
Lead 11 measures between RA and LL
Lead 111 measures between LA and L chest

24. Leads AVR,AVL and AVF records the centre of the heart to a limb
AVL measures centre of heart to LA
AVR measures centre of heart to RA
AVF measures centre of heart to L foot
The lead on the R foot is an earth lead

25. Leads Chest leads are V1, V2, V3, V4, V5, V6
Measures the front to the back of the heart

26. Limb leads
Black-left arm
White-right arm
Red-left leg
Green-right leg

27. Procedure Identify patient
Patient needs to be calm and relaxed, no pain, respect privacy, warmth
Remove top clothes, shoes, socks, jewellery
Patient to lie on back
Prepare skin, shave if necessary, use alcohol wipe, abrade skin, be aware of perspiration
Apply electrodes
Attach leads

28. Artifacts Electrical interference
Rapid vibration and spikes that widen the baseline
Look fuzzy and thick
Correct by moving machine away from bed, disconnect wall socket items, patient not to touch metal on beds

29. Artifacts 2. Movement Talking, coughing, crying, muscle tremors
Ask patient to lie with hands under buttocks
Attach leads accordingly

30. Artifacts 3. Wandering baseline
Usually due to poor electrode contact with skin
Check that the lead hasn’t come loose
Electrode may be too dry or too wet

31. Special circumstances
Amputation or plaster- place electrodes close to body
Pregnancy- document as may be slightly abnormal due to increased blood volume
Seizure- remain calm, stay with patient, call for help, do ECG after seizure is over
Large breasts- place electrodes under breast tissue

32. Troubleshooting
Plug into socket, can be used in battery mode but preferable from wall socket
Good skin contact
Warm, private environment
Simple explanation
Comfort and lying down
Label correctly

33. Review
Page 13- check review your tracing