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 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/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
3.Medium
II25 mm/s · 10 mm/mVjunctional rhythmsinus bradycardiaatrial fibrillationnormal sinus rhythm

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. 1junctional rhythm
  2. 2sinus bradycardia
  3. 3atrial fibrillation
  4. 4normal sinus rhythm
4.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 Fridericia’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
5.Hard
II25 mm/s · 10 mm/mVatrial flutter, 2:1 conductiontorsades de pointesventricular fibrillationidioventricular rhythm

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. 1atrial flutter, 2:1 conduction
  2. 2torsades de pointes
  3. 3ventricular fibrillation
  4. 4idioventricular rhythm
6.Hard
II25 mm/s · 10 mm/mVsecond-degree AV block type I (Wenckebach)third-degree (complete) AV blockfirst-degree AV blockjunctional rhythm

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. 2third-degree (complete) AV block
  3. 3first-degree AV block
  4. 4junctional rhythm

Answer key

  1. 1. heart rate = 80 bpm
  2. 2. heart rate = 107 bpm
  3. 3. junctional rhythm
  4. 4. QTc = 0.403 s
  5. 5. torsades de pointes
  6. 6. third-degree (complete) AV block

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