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 P waves! Where are you?
Lessons
42
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?
Current lesson 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
P waves! Where are you?
Identifying P waves is very important in determining where the electrical impulse within the heart is being generated.

Normal P waves that originate from the SA node move in an anterior (toward the front of the chest), and downward (toward the feet), and leftward direction. Therefore, ECG leads that measure electrical activity in these directions will show the P waves the best. As the wave of depolarization enters the left atrium, it is directed posteriorly a little bit and therefore, in lead V1 (which is good at meauring anterior-posterior), the P wave can be initially upgoing and then sometimes have a small downgoing portion at the end.

The 2 leads that show normal P waves the best are lead II (downward and to the left) and V1 (anterior):

Lead II         
lead II

V1 
precordial leads

For this reason, a "rhythm strip" on a monitor that displays only one ECG lead will usually display lead II.

P waves can be different shapes and sizes, as shown below:

These P waves have 2 small peaks:
P waves

These P waves have a small bump:
P waves

These P waves are difficult to see. Maybe another lead would show them:
P waves

These P waves are upside down, which is called inverted:
P waves

In these examples, there are no P waves:
no P waves
no P waves
no P waves

In this example, there is a lot of "garbage" in the baseline. There are no discrete well formed P waves.
wavy garbage

The red arrow points to a T wave, not a P wave.
this is a T wave, not a P wave

Now it is your turn to practice.