Emergency Department ACLS Unstable Bradycardia Megacode: How to Respond in an Emergency Situation

In this blog post, we will discuss how to respond to an emergency department ACLS unstable bradycardia megacode. This is a serious emergency situation that requires quick action.

If you are not familiar with the megacode, don’t worry! We will go over the steps that you need to take in order to provide lifesaving care for the patient.

Adult Emergency Department Unstable Bradycardia Megacode Scenario

The following is a scenario in which you would use the ED adult unstable bradycardia Megacode:

You are a healthcare provider working in the emergency department. You are assessing a woman with a history of syncopal episodes. She is present in the ED as she feels she is going to have another syncopal episode.

Demonstrate what you would do next

Initial Impression

The 75-year-old female is sitting upright on a stretcher. She is feeling dizzy, light-headed, weak, and faint. There are no complaints of chest pain, dyspnea, or palpitations. Overall she has been healthy with no recent changes to her medications.

Primary Assessment Survey (A, B, C, D, E)

Airway: The airway is patent. The flow through the trachea is not impaired.

Breathing: Oxygenation is showing 98% on room air.

Circulation: Blood pressure is 76/50, heart rate is 30/min, a rhythm check shows second-degree heart block Type II, and the pulse is present but weak.

Disability: The patient is oriented but drowsy. Overall alert, but responsive to verbal stimuli at times.

Exposure: No obvious signs of trauma, bleeding, burns, markings, or medical alert bracelet.

Change in Condition

After assessment of the initial impression and primary assessment, the patient’s mental status starts to deteriorate and the monitor shows a third-degree AV block.

What are your next actions?

  1. Check responsiveness: Tap the shoulders and shout, “Are you okay?” There is a slight response.
  2. Activate the emergency response system. Shout for backup and announce what room you are in.
  3. Check for breathing: Look for visible chest rising and falling. Breathing is present but weak.
  4. Check for a pulse: Place your fingers on the inside of the patient’s neck, just below the angle of the jaw. You will palpate the carotid pulse for no more than 10 seconds. Pulse is present but weak.

What are your next actions?

Pulse and breathing is present so we will not begin CPR starting with compressions.

Unstable Bradycardia Algorithm

Identify and Treat the Underlying Cause

  1. Maintain patent airway, assist with breathing if necessary – Airway is patent and breathing is spontaneous
  2. Oxygen (if hypoxemic) – The patient is not hypoxemic at this time and does not require oxygen.
  3. Cardiac monitor, blood pressure, oximetry – Third Degree Heart Block, BP 76/50, 98% on room air
  4. IV Access – 20 gauge in the left and right antecubital
  5. 12-Lead ECG if available and doesn’t delay therapy – Not readily available
  6. Consider hypoxic and toxicologic causes – Myocardial Ischemia/infarction, calcium-channel blockers, beta-blockers, digoxin, hypoxia, hyperkalemia

Persistent Bradyarrhthmia Causing

  • Hypotension? – YES
  • Acutely altered mental status? – YES
  • Signs of shock (low blood pressure, altered mental status, cold moist skin, weak or rapid pulse, rapid breathing, decreased urine output) – YES
  • Ischemic chest discomfort? – Unknown at this time but declined on previous assessment
  • Acute heart failure (heavy breathing, suffocating sensation, struggle to breathe while lying down, tight chest, arrhythmia, cough, fluid retention, loss of consciousness)? – YES


What interventions could you perform next?

  • Atropine 1mg bolus – relatively contraindicated in high-degree blocks

If atropine is not effective or contraindicated:

  • Transcutaneous pacing – YES
  • Dopamine
  • Epinephrine
  • Labs – electrolytes and cardiac biomarkers
  • Urinalysis
  • Fluids
  • Chest x-ray
  • Cardiac Consultation
  • Transfer to a higher level of care

You will begin the transfer to a higher level of care. Your scenario has concluded.

Jennifer Cheung


Meet Jennifer Cheung, a passionate nurse, educator, and the creative force behind ""&"" With a simple mission to help passioned healthcare professionals with "endless educational resources" across all career levels.

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