What medications are used to treat junctional bradycardia in a pediatric patient?

Medications for Pediatric Junctional Bradycardia

First-Line Treatment: Optimize Oxygenation and Ventilation

The most critical initial intervention for pediatric junctional bradycardia is ensuring adequate oxygenation and ventilation, as most pediatric bradycardia results from hypoxia rather than primary cardiac pathology. 1, 2

• Provide supplemental oxygen and ensure adequate ventilation before any pharmacologic intervention 2
• Begin bag-mask ventilation if needed, delivering 1 breath every 2-3 seconds (20-30 breaths per minute) 1
• Attach cardiac monitor and assess for signs of poor perfusion (altered mental status, hypotension, signs of shock) 1, 2

Pharmacologic Treatment Algorithm

When Heart Rate <60 bpm with Poor Perfusion Despite Adequate Oxygenation/Ventilation

Epinephrine is the primary medication for pediatric bradycardia with poor perfusion that remains unresponsive to adequate ventilation and oxygenation. 1, 2

• Epinephrine dose: 0.01 mg/kg (0.1 mL/kg of 1:10,000 concentration) IV/IO 1, 2
• Maximum single dose: 1 mg 1
• Repeat every 3-5 minutes as needed 1
• If no IV/IO access available, endotracheal dose is 0.1 mg/kg (0.1 mL/kg of 1:1,000 concentration) 1

Role of Atropine (Limited in Junctional Bradycardia)

Atropine is NOT the primary drug for most pediatric bradycardia, including junctional bradycardia. 2

• Atropine is reasonable ONLY for bradycardia caused by increased vagal tone or anticholinergic drug toxicity 1, 2
• Atropine dose: 0.02 mg/kg IV/IO 2, 3
• Minimum dose: 0.1 mg 2, 3
• Maximum single dose: 0.5 mg in children, 1.0 mg in adolescents 3
• Can repeat every 5 minutes up to maximum total dose of 1 mg in children, 2 mg in adolescents 3

Critical caveat: Atropine is unlikely to be effective for junctional bradycardia because the mechanism is enhanced automaticity from an ectopic AV junctional focus, not vagal tone 1. Atropine works by blocking vagal effects on the sinus and AV nodes, which is not the underlying problem in junctional bradycardia 4.

CPR Initiation Criteria

Begin chest compressions if heart rate remains <60 bpm with signs of poor perfusion despite adequate oxygenation and ventilation. 1

• Compression rate: 100-120 per minute 1
• Compression depth: at least one-third of anteroposterior chest diameter 1
• Compression-ventilation ratio: 15:2 with two rescuers, 30:2 with single rescuer 1
• Change compressor every 2 minutes 1

Special Considerations for Junctional Bradycardia

When Transcutaneous Pacing May Be Considered

Emergency transcutaneous pacing may be lifesaving in complete heart block or sinus node dysfunction, but is NOT helpful in bradycardia secondary to hypoxic/ischemic myocardial insult or respiratory failure. 1

• Pacing is most appropriate for structural conduction system problems (complete heart block, abnormal sinus node function) 1
• Pacing was not shown to be effective in asystole 1

Junctional Bradycardia-Specific Context

Junctional bradycardia in pediatrics typically occurs postoperatively after cardiac surgery for congenital heart disease (junctional ectopic tachycardia variant) 1. In adults, beta blockers, diltiazem, and other agents are used for junctional tachycardia, but the pediatric bradycardic variant requires the standard pediatric bradycardia algorithm focused on oxygenation, ventilation, and epinephrine 1, 2.

Common Pitfalls to Avoid

• Do not use atropine as first-line therapy for junctional bradycardia—it addresses vagal tone, not the ectopic automaticity mechanism 2, 4
• Do not delay chest compressions if heart rate <60 bpm with poor perfusion persists despite oxygenation/ventilation 1, 5
• Do not use verapamil in infants without expert consultation due to risk of myocardial depression, hypotension, and cardiac arrest 1
• Ensure IV/IO access early, as it is superior to endotracheal drug administration 2