Bradycardia Basics

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• Quick Differential: DIMES
  • D – drugs (digoxin, CCB, beta blockers, cholinergic drugs, TCAs, Clonidine)
  • I – ischemia (heart and brain)/ infection (sepsis, Lyme disease) 
  • M – metabolic (hypothyroid, hypoglycemia, hypothermia) 
  • E – electrolytes (hyperkalemia, hypokalemia, hypercalcemia, hypocalcemia, hypermagnesemia) 
  • S – sinus dysfunction (SSS, AV block) 
• Meds: 
  • 3g calcium gluconate (treats hyperK & increases inotropy) 
  • Atropine ? 
    • 0.5 – 1 mg q5min, max dose 3 mg 
    • peds = 0.02 mg/kg
    • Only effective in 28% of patients with symptomatic bradycardia 
    • Atropine shuts down the vagus nerve to remove parasympathetic stimulation to the heart….not effective for many types of bradycardia 
    • Atropine will NOT work in someone who has had a heart transplant, dat vagus nerve has already been cut. 
  • Epinephrine bolus 
    • 20-40 mcg IV (EMCRIT recommended dose using push dose epi) 
    • peds 0.01 mcg/kg in 1:10,000 concentration (code dose concentration) 
    • Epi acts on myocardia muscles, the SA node, and the AV node -> effective against a wider range of underlying pathologies and can help out your BP 
  • Epinephrine drip 2-10 mcg/min 
  • Dopamine drip 2-10 mcg/kg/min 
  • Isoproterenol is a pure beta agonist that can go through a peripheral line 
    • Last ditch med: isoproterenol reported to work really well but $$$$
    • Can also be used in refractory Torsades to shorten QTc (Thanks Dr. Littmann)
  • CONFIRM PACING BY PALPATING A PULSE (or using pulse ox pulse rate NOT rhythm strip on monitor) 
• Overdoses to consider:
  • Beta blocker OD: glucagon and high dose insulin + dextrose 
  • CCB overdose: high dose insulin + dextrose
    • CCB OD -> hyperglycemia
    • Consider in patients who are not known to be diabetic but present with lab values consistent with DKA + bradycardia + hypotension 
    • The level of hypoglycemia can serve as a marker of severity of shock 
  • Digoxin OD: Digibind
    • Potassium level correlates with level of toxicity 
    • 20 viiles for a coding patient! 
    • Dosing formula on MedCalc using serum level & amount ingested  (mg ingested x 0.8 x 2) 
• Pacing:
  • Transcutaneous Pacing:
    • https://www.youtube.com/watch?v=1fjmyog37Fo – Peds example, smoooooth voice
    • https://www.youtube.com/watch?v=5qfIRPxoHuw – adult example 
    • https://www.youtube.com/watch?v=UInoEPPjwKo – how to set up the box 
  • Transvenous Pacing:
    • https://www.youtube.com/watch?v=OMtuaBV8C2k – Set up
    • https://www.youtube.com/watch?v=00-T8PcbStE – Procedure
    • https://www.youtube.com/watch?v=9dgZfX7OK_k – trouble shooting