Methods of ECG Interpretation
There are so many different recommendations of ECG Interpretation. Some books have 5 steps, some 6, some 9, some 11. Below, I have listed a few common ones in the hope of highlighting the differences – and the similarities. I have tried to focus on rhythm strip analysis only but some methods combine the rhythm strip with the 12 lead analysis. I have only included those that are publicly available, so although some fantastic methods are taught on courses, I can’t reference them and have subsequently omitted them. However, if you have a preference or believe one method should be included below, add it in the comments and it may be featured in a future update.
Method one:
From: Resuscitation Council, Advanced Life Support (2021: 106):
The 6 Steps of rhythm strip analysis:
1. Is there any electrical activity? (Or/and check a pulse)
2. What is the ventricular (QRS) rate?
3. Is the QRS rhythm regular or irregular?
4. Is the QRS complex width normal (‘narrow’) or broad?
—
5. Is atrial activity present?
6. Is atrial activity related to ventricular activity and, if so, how?
Method Two:
From: Charles L. Till, Clinical ECGs in Paramedic Practice (2021: 16):
9 Steps – initially look at lead II, then look at every ECG lead:
ECG Steps
1. What is the rate and rhythm?
2. Are there any P waves and what is their relationship with the QRS complex?
3. What is the duration and morphology of the QRS complex?
4. Is the ST segment isoelectric, depressed or elevated?
5. Are the QT intervals and T waves normal?
Clinical Steps
6. Is the heart generating a palpable pulse of appropriate rate and providing adequate perfusion?
7. Is the rhythm unstable and at risk of deterioration?
8. Does the presenting rhythm support or change your working diagnosis?
9. Are any clinical interventions required?
Method Three:
From: Paul Murray, East of England Ambulance Service, Version 1.0, ECG Recognition – Quick Reference Guide (Feb 2014: 1)
6 steps:
1. ‘QRS Rate’
2. ‘Is the QRS rhythm regular or irregular?’ (and regularly irregular or irregularly irregular?)
3. ‘QRS duration’
4. ‘Are P waves present?’
5. ‘Relationship between P waves and QRS – is there a P wave for each QRS and a QRS for each P wave?’
6. ‘Is the PR interval within normal limits 120-200ms and is it constant?’
(This is basically the same as the RC council method, with one added step; the RC method has one step at the start – a reminder to ensure the leads are connected properly and the patient is alive).
Method Four
From: Fred Kusumoto & Pam Bernath, ECG Interpretation for Everyone – An On-The-Spot Guide (2012: 33-36):
‘Assess the patient: symptoms and physical examination. Appearance, vital signs, physical examination’ ->
1. Is there a P wave in front of every QRS and is the rate between 50-100 beats per minute?
2. Are the ST segments isoelectric?
Each answer leads you to a different figure – an option to confirm you have a normal ECG, evaluation of ST segments, evaluation of arrhythmias, or confirmation time-critical patients.
The normal ECG should have:
1. Rate should be between 50 and 100bpm
2. A P before every QRS (Positive P in lead II).
3. The QRS in V1 should be narrow an negative i.e. an Rs
4. The ST segment should be isoelectric
5. The T wave should be the same direction as the QRS
Method Five:
From: Kuhn, Lang, and Wiesbauer, ECG Mastery: The Simplest Way to Learn the ECG (2014: 141-142)
Summarised – 11 steps (taking you from rhythm analysis into 12 lead analysis. Steps included to highlight how some of the steps above are readdressed or appear later altogether here; other points may appear in front):
1. Rhythm. Criteria for sinus rhythm:
- Are the P waves positive in I and II?
- Is there a QRS complex after each P wave?
- Are the PR intervals constant?
- Are the RR intervals constant?
Ask: Is it sinus?
2. Heart rate
3. P waves – atrial enlargement present?
4. PR interval
5. QRS axis
6. QRS duration
7. Rotation
8. QRS amplitude
9. QRS infarction signs
10. ST-T segment
11. QT duration, T-U waves
That’s it for today, though you may find other methods at useful courses such as Mark Whitbread’s ECG Bootcamp.
Do you have any recommendations, preferences, or opinions? Add them below!
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