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

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
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/mVfirst-degree AV blocksinus rhythm with PVCsventricular bigeminyatrial 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. 1first-degree AV block
  2. 2sinus rhythm with PVCs
  3. 3ventricular bigeminy
  4. 4atrial fibrillation
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 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
5.Hard
II25 mm/s · 10 mm/mVsinus rhythm with wide QRSdual-chamber (AV) paced rhythmidioventricular rhythmventricular paced 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. 1sinus rhythm with wide QRS
  2. 2dual-chamber (AV) paced rhythm
  3. 3idioventricular rhythm
  4. 4ventricular paced rhythm
6.Hard
II25 mm/s · 10 mm/mVtorsades de pointesasystoleventricular fibrillationatrial flutter, 4:1 conduction

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. 2asystole
  3. 3ventricular fibrillation
  4. 4atrial flutter, 4:1 conduction

Answer key

  1. 1. PR = 0.28 s
  2. 2. heart rate = 60 bpm
  3. 3. sinus rhythm with PVCs
  4. 4. QTc = 0.5 s
  5. 5. ventricular paced rhythm
  6. 6. ventricular fibrillation

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