The rhythm on this lead II strip is regular. Use the 300 method (300 ÷ the number of large boxes between two consecutive R waves) to estimate the heart rate in beats per minute, rounded to a whole number.
ECG rhythm strip interpretation worksheet with answers
1.Easy
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
heart rate = bpm
2.Easy
Look at the R–R intervals on this lead II strip. How would you describe the ventricular rhythm? Click your answer.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
- 1regular
- 2regularly irregular
- 3irregularly irregular
3.Medium
This lead II strip shows atrial flutter. How many flutter waves per QRS complex are there (the n of n:1 conduction)?
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
flutter waves per QRS =
4.Medium
Interpret this lead II rhythm strip. Which rhythm is it? Click your answer.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
- 1atrial flutter, 3:1 conduction
- 2normal sinus rhythm
- 3atrial fibrillation
- 4atrial flutter, 4:1 conduction
5.Hard
Identify the rhythm on this lead II strip. Click your answer.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
- 1sinus bradycardia
- 2junctional rhythm
- 3asystole
- 4third-degree (complete) AV block
6.Hard
This lead II strip shows an AV block with an irregular ventricular rhythm. Use the 6-second method to find the ventricular rate in beats per minute.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
ventricular rate = bpm
Answer key
- 1. heart rate = 43 bpm
- 2. regularly irregular
- 3. flutter waves per QRS = 4
- 4. atrial flutter, 3:1 conduction
- 5. asystole
- 6. ventricular rate = 50 bpm
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