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.
ECG rhythm strip interpretation worksheet with answers
1.Easy
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
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
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
- 1sinus rhythm with PVCs
- 2junctional rhythm
- 3sinus arrhythmia
- 4atrial fibrillation
4.Medium
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
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
- 1supraventricular tachycardia (SVT)
- 2ventricular fibrillation
- 3torsades de pointes
- 4idioventricular rhythm
6.Hard
A patient without a palpable pulse has this organised rhythm on the monitor (pulseless electrical activity). Which treatment do adult resuscitation guidelines name for 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
- 1immediate defibrillation
- 2transcutaneous pacing
- 3synchronised cardioversion
- 4CPR (non-shockable rhythm)
Answer key
- 1. heart rate = 71 bpm
- 2. PR = 0.16 s
- 3. atrial fibrillation
- 4. QTc = 0.464 s
- 5. torsades de pointes
- 6. CPR (non-shockable rhythm)
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