How to Diagnose ANY Cardiac Rhythm Systematically

ecg heart flatline

Narrow complex tachycardia…hmm, but isn’t that supraventricular tachycardia?

Broad complex tachycardia…VT…no wait, it’s VF…hang on, asystole (oh, oh!)

It’s atrial fibrillation…wait, what about atrial flutter?

Regular, no wait…is that irregular?

Let’s not forget all those different heart blocks…

What happened to a good ol’ run of straight forward sinus rhythm?

With so many cardiac rhythms to remember, wouldn’t it be nice to be able to get to the correct diagnosis each and every time? The beauty about cardiac rhythms are that they are all fairly predictable. If you ask the right questions in a systematic manner, it will get you to diagnosing the right cardiac rhythm pretty much every time! Don’t believe me? Why not give it a shot by using this flowchart I have designed to do just that:

cardiac ECG rhythm analysis flow chart

Now that you’ve had a chance to have a good look through the flowchart above, why not put it to the test? Make your way through the following cardiac rhythms utilising the flowchart!

Practice Makes Perfect

sinus tachycardia ECG

What is the diagnosis of the cardiac rhythm above?
Click for the answer…
 Sinus Tachycardia
1) There are upright, smooth and rounded P waves
2) Every P wave is followed by a QRS complex in a 1:1 ratio
3) The PR interval is < 0.2 seconds in length
4) The rate is > 100 bpm

atrial fibrillation ecg

What is the diagnosis of the cardiac rhythm above?
Click for the answer…
 Atrial Fibrillation
1) There are no clear upright, smooth and rounded P waves
2) There are QRS complexes present and they are all narrow (< 0.1 seconds in width)
3) The rhythm is not regular

3rd degree AV heart block ecg

What is the diagnosis of the cardiac rhythm above?
Click for the answer…
Third Degree Heart Block
1) There are upright, smooth and rounded P waves
2) There is no 1:1 ratio between the P waves and QRS complex
3) The QRS complexes are all broad (> 0.1 seconds in width)

junctional rhythm ecg

What is the diagnosis of the cardiac rhythm above?
Click for the answer…
 Junctional Rhythm
1) There are no clear upright, smooth and rounded P waves
2) There are QRS complexes present and they are all narrow (< 0.1 seconds in width)
3) The rhythm is regular
4) There are no “saw tooth” flutter waves
5) The rate is not > 100 bpm
6) The rate is between 40 – 60 bpm

2nd degree Heart block type 1 wenkebach ecg

What is the diagnosis of the cardiac rhythm above?
Click for the answer…
2nd Degree Heart Block – Type 1
1) There are upright, smooth and rounded P waves
2) Not every P wave is followed by a QRS complex in a 1:1 ratio
3) The QRS complexes are all narrow (< 0.1 seconds in width)
4) There is a progressive lengthening of the PR interval

2nd degree heart block type 2 ecg

What is the diagnosis of the cardiac rhythm above?
Click for the answer…
2nd Degree Heart Block – Type 2
1) There are upright, smooth and rounded P waves
2) Not every P wave is followed by a QRS complex in a 1:1 ratio
3) The QRS complexes are all narrow (< 0.1 seconds in width)
4) The PR intervals are all the same width

atrial flutter ECG

What is the diagnosis of the cardiac rhythm above?
Click for the answer…
 Atrial Flutter (Fixed Block)
1) There are no clear upright, smooth and rounded P waves
2) There are QRS complexes present and they are all narrow (< 0.1 seconds in width)
3) The rhythm is regular
4) There are “saw tooth” flutter waves

1st degree heart block ecg

What is the diagnosis of the cardiac rhythm above?
Click for the answer…
 1st Degree Heart Block
1) There are upright, smooth and rounded P waves
2) Every P wave is followed by a QRS complex in a 1:1 ratio
3) The PR interval is > 0.2 seconds in length 

idioventricular rhythm ecg

What is the diagnosis of the cardiac rhythm above?
Click for the answer…
 Idioventricular Rhythm
1) There are no clear upright, smooth and rounded P waves
2) There are QRS complexes present and they are all broad (> 0.1 seconds in width)
3) The rhythm is regular
4) The rate is < 100 bpm

ventricular tachycardia VT ECG

What is the diagnosis of the cardiac rhythm above?
Click for the answer…
 Ventricular Tachycardia or Supraventricular Tachycardia with Aberration
1) There are no clear upright, smooth and rounded P waves
2) There are QRS complexes present and they are all broad (> 0.1 seconds in width)
3) The rhythm is regular
4) The rate is > 100 bpm

supraventricular tachycardia SVT ECG

What is the diagnosis of the cardiac rhythm above?
Click for the answer…
 Supraventricular Tachycardia
1) There are no clear upright, smooth and rounded P waves
2) There are QRS complexes present and they are all narrow (< 0.1 seconds in width)
3) The rhythm is regular
4) There are no “saw tooth” flutter waves
5) The rate is > 100 bpm
6) P waves are indiscernible

ventricular fibrillation VF ECG

What is the diagnosis of the cardiac rhythm above?
Click for the answer…
 Ventricular Fibrillation
1) There are no clear upright, smooth and rounded P waves
2) There are no clear QRS complexes
3) There is electrical activity still evident 

asystole

What is the diagnosis of the cardiac rhythm above?
Click for the answer…
Asystole
1) There are no clear upright, smooth and rounded P waves
2) There are no clear QRS complexes
3) There is no electrical activity still evident 

As you hopefully have seen, you will be able to diagnose the vast majority of rhythms that come your way if you have a systematic process! Just get yourself into a routine and if you keep working at it, all these rhythms will straighten themselves out in the end…much like the last rhythm strip proved!

References

  • Wagner, G. S., & Strauss, D. G. (2014). Marriott’s practical electrocardiography (12th ed.). Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins.
  • Wesley, K. (2017). Huszar’s ECG and 12 lead interpretation (2nd ed.). Missouri: Elsevier.

If you liked this post, why not subscribe to Blogging for your Noggin? Be one of the first to know when new content becomes available! I promise there will be no annoying spam! 

Enter your email address to follow this blog and receive notifications of new posts by email.

 

Advertisements

8 thoughts on “How to Diagnose ANY Cardiac Rhythm Systematically

  1. Thanks a lot for sharing this with all of us you actually know what you’re talking about! Bookmarked. Kindly also visit my website =). We could have a link exchange contract between us!

    Like

    • Thank you so much for your lovely feedback! So glad to hear that the information posted is enjoyable and clinically relevant 🙂 If you ever have any suggestions for new post topics, let me know!

      Jo

      Like

Do you have a question? Or a suggestion for a new topic?

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s