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/mVregularregularly irregularirregularly irregular

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
  1. 1regular
  2. 2regularly irregular
  3. 3irregularly irregular
3.Medium
II25 mm/s · 10 mm/mV

Measure the QT interval and the R–R interval on this regular lead II strip, then calculate the rate-corrected QTc with Bazett’s formula QTc = QT/√RR (both in seconds). Give the answer in seconds to three decimals.

lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
QTc = s
4.Medium
II25 mm/s · 10 mm/mVsinus rhythm with PVCsatrial fibrillationatrial flutter, 2:1 conductionatrial flutter, 4:1 conduction

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. 1sinus rhythm with PVCs
  2. 2atrial fibrillation
  3. 3atrial flutter, 2:1 conduction
  4. 4atrial flutter, 4:1 conduction
5.Hard
II25 mm/s · 10 mm/mVdual-chamber (AV) paced rhythmthird-degree (complete) AV blockpaced rhythm, failure to captureidioventricular rhythm

This patient has a pacemaker. Interpret the 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
  1. 1dual-chamber (AV) paced rhythm
  2. 2third-degree (complete) AV block
  3. 3paced rhythm, failure to capture
  4. 4idioventricular rhythm
6.Hard
II25 mm/s · 10 mm/mV

This lead II strip shows second-degree AV block type I (Wenckebach). Measure the PR interval of the last conducted beat before a non-conducted P wave (the longest PR), in seconds.

lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
longest PR = s

Answer key

  1. 1. heart rate = 83 bpm
  2. 2. regularly irregular
  3. 3. QTc = 0.51 s
  4. 4. atrial fibrillation
  5. 5. paced rhythm, failure to capture
  6. 6. longest PR = 0.34 s

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