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.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
II25 mm/s · 10 mm/mV

This 6-second lead II strip is irregular, so the 300 and 1500 methods do not work. Use the 6-second method to estimate the ventricular heart rate in beats per minute.

lead II, 25 mm/s, 10 mm/mVstrip length 6 s (marks at 0, 3 and 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/mV

Measure the QT 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
QT = s
5.Hard
II25 mm/s · 10 mm/mVidioventricular rhythmventricular paced rhythmthird-degree (complete) AV blockpaced rhythm, failure to capture

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. 1idioventricular rhythm
  2. 2ventricular paced rhythm
  3. 3third-degree (complete) AV block
  4. 4paced rhythm, failure to capture
6.Hard
II25 mm/s · 10 mm/mVfirst-degree AV blocksecond-degree AV block type I (Wenckebach)junctional 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. 1first-degree AV block
  2. 2second-degree AV block type I (Wenckebach)
  3. 3junctional rhythm
  4. 4third-degree (complete) AV block

Answer key

  1. 1. heart rate = 60 bpm
  2. 2. irregularly irregular
  3. 3. QTc = 0.505 s
  4. 4. QT = 0.48 s
  5. 5. ventricular paced rhythm
  6. 6. third-degree (complete) AV block

Full step-by-step solutions: practise this topic on examproblems.com.