ECG rhythm strip interpretation worksheet with answers

Free printable ECG rhythm strip interpretation worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
II25 mm/s · 10 mm/mV

This lead II rhythm is regular. Count the small boxes between two consecutive R waves and use the 1500 method to find the heart rate in beats per minute, rounded to a whole number.

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
II25 mm/s · 10 mm/mV

Measure the PR interval on this lead II strip, in seconds.

lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
PR = s
3.Medium
II25 mm/s · 10 mm/mVnormal sinus rhythmjunctional rhythmfirst-degree AV blockatrial fibrillation

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
  1. 1normal sinus rhythm
  2. 2junctional rhythm
  3. 3first-degree AV block
  4. 4atrial fibrillation
4.Medium
II25 mm/s · 10 mm/mV

This lead II strip shows sinus rhythm with one pause. Measure the pause, the R–R interval across it, in seconds.

lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
pause = s
5.Hard
II25 mm/s · 10 mm/mVsecond-degree AV block type II2:1 AV block (type undetermined)sinus bradycardiathird-degree (complete) AV block

Interpret this lead II strip. Which interpretation can you defend from this single 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
  1. 1second-degree AV block type II
  2. 22:1 AV block (type undetermined)
  3. 3sinus bradycardia
  4. 4third-degree (complete) AV block
6.Hard
II25 mm/s · 10 mm/mVsecond-degree AV block type I (Wenckebach)second-degree AV block type IIjunctional rhythmthird-degree (complete) AV block

This lead II strip shows a conduction problem between the atria and the ventricles. 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
  1. 1second-degree AV block type I (Wenckebach)
  2. 2second-degree AV block type II
  3. 3junctional rhythm
  4. 4third-degree (complete) AV block

Answer key

  1. 1. heart rate = 107 bpm
  2. 2. PR = 0.36 s
  3. 3. junctional rhythm
  4. 4. pause = 1.4 s
  5. 5. 2:1 AV block (type undetermined)
  6. 6. third-degree (complete) AV block

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