PALS Pediatric Arrhythmia Recognition 2 — Questions and Answers
Question 1: A 6-month-old infant has a heart rate of 240 bpm with poor perfusion and no P waves visible on ECG. What is the most appropriate initial treatment if IV access is unavailable?
- Synchronized cardioversion at 0.5–1 J/kg (Correct answer)
- Defibrillation at 2 J/kg
- Adenosine 0.1 mg/kg IV
- Amiodarone 5 mg/kg IV
Correct answer: Synchronized cardioversion at 0.5–1 J/kg
Unstable SVT without IV/IO access is treated with synchronized cardioversion starting at 0.5–1 J/kg.
Question 2: Which ECG finding distinguishes sinus tachycardia from SVT in an infant?
- Presence of visible P waves with a rate that varies with activity (Correct answer)
- Rate consistently above 300 bpm
- Wide QRS complexes
- Absent T waves
Correct answer: Presence of visible P waves with a rate that varies with activity
Sinus tachycardia has identifiable P waves and rate variability with stimulation, whereas SVT is typically fixed and lacks visible P waves.
Question 3: A child is found in cardiac arrest with a shockable rhythm. What is the correct initial defibrillation dose in PALS?
- 2 J/kg (Correct answer)
- 1 J/kg
- 4 J/kg
- 0.5 J/kg
Correct answer: 2 J/kg
PALS guidelines recommend an initial defibrillation dose of 2 J/kg for VF or pVT, increasing to 4 J/kg for subsequent shocks.
Question 4: Which of the following is a non-shockable cardiac arrest rhythm?
- Asystole (Correct answer)
- Ventricular fibrillation
- Pulseless ventricular tachycardia
- Coarse ventricular fibrillation
Correct answer: Asystole
Asystole is a non-shockable rhythm; treatment focuses on high-quality CPR and epinephrine rather than defibrillation.
Question 5: A wide-complex tachycardia at 180 bpm with a pulse is seen in a child with mild symptoms. What should be done first to differentiate VT from SVT with aberrancy?
- Obtain a 12-lead ECG and assess clinical history (Correct answer)
- Administer adenosine immediately
- Perform synchronized cardioversion
- Administer amiodarone
Correct answer: Obtain a 12-lead ECG and assess clinical history
A 12-lead ECG combined with clinical context helps differentiate VT from SVT with aberrant conduction before pharmacologic intervention.
Question 6: In a child with bradycardia and a pulse that is unresponsive to oxygenation and ventilation, what is the heart rate threshold at which CPR should be initiated?
- Less than 60 bpm with poor perfusion (Correct answer)
- Less than 80 bpm
- Less than 100 bpm
- Less than 40 bpm regardless of perfusion
Correct answer: Less than 60 bpm with poor perfusion
PALS guidelines state CPR should begin if heart rate is <60 bpm with signs of poor perfusion despite adequate oxygenation and ventilation.
PALS Pediatric Arrhythmia Recognition 2
A 6-month-old infant has a heart rate of 240 bpm with poor perfusion and no P waves visible on ECG.
What is the most appropriate initial treatment if IV access is unavailable?