PALS Pediatric Arrhythmia Recognition 1 — Questions and Answers
Question 1: Which ECG finding is characteristic of ventricular fibrillation (VF) in a child?
- Chaotic, irregular waveforms with no identifiable P waves or QRS complexes (Correct answer)
- Regular narrow-complex rhythm with rate >220 bpm
- Wide-complex tachycardia with identifiable P waves
- Sawtooth flutter waves at 300 bpm
Correct answer: Chaotic, irregular waveforms with no identifiable P waves or QRS complexes
VF is characterized by chaotic, disorganized electrical activity with no discernible P waves or QRS complexes on ECG.
Question 2: A child presents with a heart rate of 280 bpm, narrow QRS, and no discernible P waves. Which arrhythmia is most likely?
- Supraventricular tachycardia (SVT) (Correct answer)
- Sinus tachycardia
- Ventricular tachycardia
- Third-degree heart block
Correct answer: Supraventricular tachycardia (SVT)
SVT typically presents with rates >220 bpm in infants or >180 bpm in children, narrow QRS complexes, and absent or retrograde P waves.
Question 3: Which rhythm is most commonly associated with pulseless cardiac arrest in children?
- Asystole or pulseless electrical activity (PEA) (Correct answer)
- Ventricular fibrillation
- Supraventricular tachycardia
- First-degree AV block
Correct answer: Asystole or pulseless electrical activity (PEA)
Asystole and PEA are the most common arrest rhythms in children, unlike adults where VF is more common.
Question 4: On ECG, a child has a regular rhythm at 40 bpm with P waves that bear no relationship to QRS complexes. What is this rhythm?
- Third-degree (complete) AV block (Correct answer)
- Second-degree AV block type I
- First-degree AV block
- Junctional escape rhythm
Correct answer: Third-degree (complete) AV block
Complete AV block shows no association between P waves and QRS complexes, with the atria and ventricles beating independently.
Question 5: A child in cardiac arrest has a rhythm showing organized electrical activity on the monitor but no pulse. What rhythm is this?
- Pulseless electrical activity (PEA) (Correct answer)
- Asystole
- Ventricular fibrillation
- Sinus bradycardia
Correct answer: Pulseless electrical activity (PEA)
PEA is defined as organized electrical activity on the cardiac monitor without a detectable pulse.
Question 6: Which arrhythmia in a child with a pulse is treated with adenosine as the first-line pharmacologic therapy?
- Supraventricular tachycardia (SVT) (Correct answer)
- Ventricular tachycardia
- Atrial flutter
- Sinus tachycardia
Correct answer: Supraventricular tachycardia (SVT)
Adenosine is the first-line drug for stable SVT in children because it temporarily blocks AV nodal conduction to terminate the reentrant circuit.
PALS Pediatric Arrhythmia Recognition 1
Which ECG finding is characteristic of ventricular fibrillation (VF) in a child?