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/mV

The rhythm on this lead II strip is regular. Use the 300 method (300 ÷ the number of large boxes between two consecutive R waves) to estimate 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/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/mVsecond-degree AV block type IIsinus arrhythmiasinus rhythm with sinus arrestsinus bradycardia

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. 1second-degree AV block type II
  2. 2sinus arrhythmia
  3. 3sinus rhythm with sinus arrest
  4. 4sinus bradycardia
5.Hard
II25 mm/s · 10 mm/mVidioventricular rhythmsinus rhythm with wide QRSpaced rhythm, failure to capturedual-chamber (AV) 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. 1idioventricular rhythm
  2. 2sinus rhythm with wide QRS
  3. 3paced rhythm, failure to capture
  4. 4dual-chamber (AV) paced rhythm
6.Hard
II25 mm/s · 10 mm/mVsinus bradycardia2:1 AV block (type undetermined)second-degree AV block type I (Wenckebach)first-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. 1sinus bradycardia
  2. 22:1 AV block (type undetermined)
  3. 3second-degree AV block type I (Wenckebach)
  4. 4first-degree AV block

Answer key

  1. 1. heart rate = 107 bpm
  2. 2. heart rate = 55 bpm
  3. 3. QTc = 0.5 s
  4. 4. sinus rhythm with sinus arrest
  5. 5. dual-chamber (AV) paced rhythm
  6. 6. 2:1 AV block (type undetermined)

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