ACLS: Bradycardia

Background

• Only intervene if pt is symptomatic (hypotension, AMS, chest pain, pulm edema)

Categories

1. Sinus node dysfunction
   1. Sinus bradycardia
   2. Sinus arrest
   3. Tachy-brady syndrome (sick sinus)
   4. Chronotropic incompetence
2. AV node dysfunction
   1. 1st degree AV block
   2. 2nd degree AV block Mobitz I/Wenckebach
   3. 2nd degree AV block Mobitz II
   4. 3rd degree AV block (complete heart block)

Differential

1. Ischemia/Infarction
   1. Inferior MI (involving RCA)
2. Neurocardiogenic/reflex-mediated
   1. Increased ICP
   2. Vasovagal reflex
   3. Hypersensitive carotid sinus syndrome
   4. Intra-abdominal hemorrhage (i.e. ruptured ectopic)
3. Metabolic/endocrine/environmental
   1. Hyperkalemia
   2. Hypothermia
   3. Hypothyrodism
4. Toxicologic
   1. Digoxin toxicity
5. Infectious/Postinfectious
   1. Chagas dz
   2. Lyme dz
   3. Syphilis

Treatment

• Transcutaneous pacing
• Chronotropes
  • Dopamine 2-10mcg/kg/min
  • Epinephrine 2-10mcg/min
• Atropine
  • Can be used as temporizing measure (while awaiting pacing and/or chronotropes)
  • Use cautiously in pts w/ ongoing ischemia (tachycardia may worsen ischemia)
  • 0.5mg q3-5min
• Transvenous pacing
  • Required if transcutaneous pacing + chronotropes is ineffective

See Also

• ACLS (Main)
• Bradycardia (Wide)