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 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/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/mVatrial flutter, 4:1 conductionnormal sinus rhythmatrial flutter, 2:1 conductionatrial flutter, 3:1 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. 1atrial flutter, 4:1 conduction
  2. 2normal sinus rhythm
  3. 3atrial flutter, 2:1 conduction
  4. 4atrial flutter, 3:1 conduction
5.Hard
II25 mm/s · 10 mm/mV2:1 AV block (type undetermined)second-degree AV block type I (Wenckebach)sinus bradycardiafirst-degree 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. 12:1 AV block (type undetermined)
  2. 2second-degree AV block type I (Wenckebach)
  3. 3sinus bradycardia
  4. 4first-degree AV block
6.Hard
II25 mm/s · 10 mm/mVtorsades de pointesidioventricular rhythmventricular fibrillationsupraventricular tachycardia (SVT)

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
  1. 1torsades de pointes
  2. 2idioventricular rhythm
  3. 3ventricular fibrillation
  4. 4supraventricular tachycardia (SVT)

Answer key

  1. 1. heart rate = 45 bpm
  2. 2. PR = 0.32 s
  3. 3. QTc = 0.447 s
  4. 4. atrial flutter, 4:1 conduction
  5. 5. 2:1 AV block (type undetermined)
  6. 6. torsades de pointes

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