PEARS Pediatric Dysrhythmia Recognition 2 — Questions and Answers
Question 1: What is the most common cause of bradycardia in infants and young children?
- Complete heart block
- Hypoxia (Correct answer)
- Beta-blocker toxicity
- Sick sinus syndrome
Correct answer: Hypoxia
Hypoxia is the most common cause of bradycardia in infants and young children; treating the hypoxia typically resolves the bradycardia.
Question 2: Which ECG pattern is associated with Wolff-Parkinson-White (WPW) syndrome?
- Prolonged QT interval with wide T waves
- Delta wave with a shortened PR interval (Correct answer)
- Right bundle branch block with ST changes
- Peaked T waves with a wide QRS
Correct answer: Delta wave with a shortened PR interval
WPW syndrome is identified by a delta wave (slurred QRS upstroke) and shortened PR interval caused by an accessory conduction pathway that pre-excites the ventricles.
Question 3: A child is in cardiac arrest with ventricular fibrillation. What energy dose is used for the first defibrillation?
- 0.5 J/kg
- 2 J/kg (Correct answer)
- 4 J/kg
- 10 J/kg
Correct answer: 2 J/kg
The initial defibrillation dose for children with VF or pulseless VT is 2 J/kg, with escalation to 4 J/kg for subsequent shocks.
Question 4: Which rhythm is characterized by absent P waves, narrow QRS complexes, and a rate of 40-60 bpm?
- Sinus bradycardia
- First-degree AV block
- Junctional escape rhythm (Correct answer)
- Idioventricular rhythm
Correct answer: Junctional escape rhythm
A junctional escape rhythm occurs when the AV node acts as pacemaker, producing narrow QRS complexes at 40-60 bpm with absent or retrograde P waves.
Question 5: In third-degree (complete) AV block, what is the relationship between P waves and QRS complexes?
- Each P wave is followed by a progressively longer PR interval until a QRS is dropped
- P waves and QRS complexes are completely independent with no consistent relationship (Correct answer)
- Every other P wave is conducted with a normal PR interval
- P waves are absent but QRS complexes occur regularly
Correct answer: P waves and QRS complexes are completely independent with no consistent relationship
In complete AV block, the atria and ventricles beat independently—there is no consistent PR relationship between P waves and QRS complexes.
Question 6: What is the most common cause of sinus tachycardia in a child?
- Re-entrant electrical pathway in the AV node
- Fever, pain, anxiety, or hypovolemia (Correct answer)
- Digitalis toxicity
- Congenital accessory conduction pathway
Correct answer: Fever, pain, anxiety, or hypovolemia
Sinus tachycardia in children is most commonly a secondary physiologic response to fever, pain, anxiety, or hypovolemia, not a primary arrhythmia.
Question 7: What is the first-line drug for stable SVT in a child when vagal maneuvers have failed?
- Amiodarone
- Adenosine (Correct answer)
- Lidocaine
- Epinephrine
Correct answer: Adenosine
Adenosine is the first-line pharmacological treatment for stable SVT in children after vagal maneuvers have failed, given as a rapid IV bolus.
PEARS Pediatric Dysrhythmia Recognition 2
What is the most common cause of bradycardia in infants and young children?