Step 5 QRS Complex ECG Interpretation

Description

• The QRS represents ventricular depolarization.
• It is very important to analyze each QRS complex on the tracing and report the duration measurement and describe the shape (including any changes in shape).
• As discussed earlier in step 3, when referring to P waves, remember changes in the shape of the waveform can indicate the locus of stimulation has changed or a different conduction pathway was followed. It is no different when analyzing the QRS complex.
• The difference is that in step 3, we were looking at atrial activity. Now we are looking at ventricular activity.
• Measure QRS complex from the beginning to the end of ventricular depolarization.

Description 2

• The normal duration of the QRS complex measures from: 0.06 – 0.10 second
• When the QRS measurement is 0.12 seconds or greater it indicates a delay in the electrical impulse as it is passing through the ventricular conduction system
• Abnormal duration QRS

QRS Measurement 1

Analyze this tracing. What is the QRS duration?

Reveal Answer

2 small boxes (2 X 0.04 second) = 0.08 second

QRS Measurement 2

Analyze this tracing. What is the QRS duration?

Reveal Answer

4 1/2 small boxes (1/2 X 0.04 second) = 0.18 second