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TICU Atrial Fibrillation Treatment Algorithm

Division of Trauma and Surgical Critical Care
Updated May 2024

1. Initial Evaluation

  • Confirm atrial fibrillation on more than one ECG lead
  • Obtain:
  • CBC, BMP, Magnesium, Calcium, Phosphorus
  • ± Troponin
  • Chest X-ray (CXR)
  • Assess volume status and oxygenation

2. Ventricular Response?

A. No Rapid Ventricular Response (RVR)

  • No acute intervention required
  • Resume rate or rhythm controlling home medications when able

B. Rapid Ventricular Response Present

Is the patient hemodynamically unstable?

Signs of instability: Hypotension, altered mental status, ischemia, shock

3. Hemodynamically Unstable → Immediate Intervention

  • Perform synchronized cardioversion
  • Energy: 100–200 Joules
  • Pre-medicate with sedative if possible
  • Administer Magnesium 4 g IV

4. Hemodynamically Stable → Rate Control Pathway

Preferred Agents

  • Diltiazem (avoid if EF < 40% or hypotensive):
  • 0.25 mg/kg IV push × 1
  • If inadequate response, repeat 0.35 mg/kg IV push × 1

  • If still no response, start continuous infusion 5–15 mg/hr

  • Metoprolol (especially if concern for hypotension or persistent hypotension post diltiazem):

  • 5–10 mg IV every 5 minutes × up to 3 doses

  • Magnesium sulfate 4 g IV (can be used as adjunctive therapy; especially helpful in COPD/asthma)

5. Alternative or Escalation Options

If rate remains uncontrolled or rhythm persists:

  • Amiodarone:
  • 150 mg IV bolus
  • Then start infusion:
    • 1 mg/min × 6 hrs
    • Then 0.5 mg/min × 18 hrs

  • May repeat 150 mg boluses or increase rate back to 1 mg/min if AF with RVR persists

  • Digoxin:

  • Initial dose: 0.25–0.5 mg IV
  • May repeat 0.25 mg every 6 hrs
  • Maximum: 1.5 mg over 24 hours
  • Use if first- and second-line agents are ineffective or contraindicated

6. Additional Considerations

  • Identify and address reversible causes:
  • Fluid overload
  • Infection/sepsis
  • Post-operative status

  • Withdrawal, endocrine, or metabolic causes

  • Reassess rhythm and rate control efforts after 24 hours

  • Titrate HR to <110 bpm if hemodynamics allow
  • Anticoagulation discussion and documentation required if:
  • New-onset AF persists for >48 hours
  • Cardiology consult if RVR persists despite escalation

7. Authors

  • Jill Streams, MD, FACS
  • Leanne Atchison, PharmD
  • Diana Williams, AGACNP-BC