Teaching Medicine - Tutorial: Analyze the Waveforms

ECG

Level 1

Tutorial: Analyze the Waveforms

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Tutorial: Analyze the Waveforms

This module will teach the basic waveforms on ECG and a stepwise approach of how to analyze them. Practice each step and get feedback on your performance.

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Tutorial: Analyze the Waveforms Do you have Rhythm?

Lessons

Times Practiced

1284

Cases Completed

1h 24m

Total Time spent

1m 24s

Average Time

Progress

Accuracy

Efficiency

Accuracy

Efficiency

	1	Anatomy Anatomy
	2	Waveform Identification Waveform Identification
	3	Waveform Identification #2 Waveform Identification #2
	4	Determine the heart rate Determine the heart rate
	5	Do you have Rhythm? Do you have Rhythm?
	6	P waves! Where are you? P waves! Where are you?
	7	How many P waves? How many P waves?
	8	P wave Size and Shape P wave Size and Shape
	9	PR Interval PR Interval
	10	P conducted to QRS? P conducted to QRS?
	11	QRS Width QRS Width

Practice

Do you have Rhythm?

When you analyze rhythm, you are asking if the spacing between the QRS's is all the same, or if it is different. There are essentially 4 different rhythm categories:

regular
regular with random extra or missing beats
irregular with a pattern
irregular without a pattern

Regular
This occurs when the timing or spacing between each heart beat is equal. Below are some examples of regular rhythms. Notice that the rate in each example is different, but if you measure the spacing of QRS's in each one, the spacing remains constant.

Notice also that the shape and size of the QRS is also different in each example. Do not let this detail distract you from the fact that the rhythm is regular in every example.

Regular with Extra or Missing Beats
There are 2 situations where this can occur:

An extra heartbeat from a different part of the heart is generated and this will create an extra beat, often earlier than expected
An expected beat for some reason or another, does not occur, resulting in a missed beat.

Here are some examples of extra beats. Notice that the "extra" QRS size and shape can be different.
One extra early beat

Here are some examples of regular rhythm with missing QRS's.
one missing QRS complex

Irregular with a pattern (also called regularly irregular)
In these rhythms, they are not regular like clockwork, but they do have a pattern. For example, some patterns could be:

3 beats then a missed beat, 3 beats then a missed beat
2 beats then an early beat, 2 beats then an early beat
1 beat then an early beat, 1 beat then an early beat

2 beats followed by an early beat, repeating:
irregular with a pattern

1 wide beat followed by an early narrow beat, repeating:
irregular with a pattern

Irregular with no pattern (irregularly irregular):
In these examples, there is no discernable rhythm. The spacing between each QRS changes with every heartbeat. Sometimes the changes are very small and you need calipers to see that they are not equal.

Take your own pulse now. Is it regular? It is normal to have occasional extra or missed beats, so don't panic if you are not 100% regular. Also, take some deep breaths in and out. Can you feel your heart rate increase with breathing in and decrease with breathing out? This is normal. It does not mean your heart rhythm is irregular. It only means that the rate is changing with your breathing. Again, this is normal.

Before you do this practice session, let us tell you about the calipers. On a desktop computer, to make the caliper appear, click on the ECG image:
how to calipers

It will look like this:
how to calipers

Click on the main body of the calipers to move them:
how to calipers

Click and drag grey circle to re-size:
how to calipers

Bottom left corner gives heart rate calculation:
how to calipers

Use the calipers to check the distance from QRS to QRS to see if it is constant.

Please note: I frequently am asked if a rhythm is regular or irregular when there are MINOR differences between the QRS complexes. There is no "exact" percent difference and you have to practice a few before your eye and brain become confident.

Go practice your rhythm.