Sinus Bradycardia

 Treatment

• Only treat if < 50bpm and evidence of hypoperfusion
• Transcutaneous cardiac pacing  
• Usually 50-100 mA, but may need up to 200mA
• Only Class I treatment for unstable patients
  
• Lorazepam (1-2mg IV) or morphine (2-4mg IV) for pain control
  
• Atropine
• 0.5mg push every 3-5 minutes, 3mg total max
• Epinephrine
• 2-10 micrograms/min IV
• Can also use dopamine
• Treat beta-blocker or CCB toxicity if present
• Glucagon 3-10mg IV over 1-2 minutes; then 1-5mg per hour
  

        

Causes

• Physiologic (vagal tone)
• Pharmacologic (CCBs, Beta-blockers, digoxin)
• Pathologic (Acute inferior MI, ICP, carotid sinus hypersensitivity, hypothyroid, sick sinus)

 

Notes

• Slow or low-dose administration of atropine can cause paradoxical bradycardia
• Atropine ineffective on heart-transplant patients