Anesthesia for Cardioversion

Cardioversion Basics - Shocking Rhythms Right

• Indications: Atrial Fibrillation (AF), Atrial Flutter, Ventricular Tachycardia (VT) with pulse, Supraventricular Tachycardia (SVT).
• Types: Elective (stable) vs. Emergency (unstable).
• Synchronization:
  • Synchronized: Shock on R-wave (AF, AFlutter, stable VT).
  • Unsynchronized (Defibrillation): Shock anytime (pulseless VT/VF).
• Energy (Biphasic):
  • AF: 100-200J.
  • AFlutter/SVT: 50-100J.
  • VT (pulse): 50-100J (sync).
• 📌 'Sync for Slower folks with QRS, Defib for Dead/Dying fast'.

⭐ Synchronized cardioversion delivers shock on R-wave to avoid R-on-T phenomenon (preventing VF), crucial for treating tachyarrhythmias like AF, atrial flutter, and stable VT.

Pre-Anesthetic Prep - Safety First Scan

• Patient Assessment:
  • ABCDE, ASA status, comorbidities.
  • Airway: Mallampati, NPO (6-8h solids, 2h clear fluids).
• Anticoagulation (AF >48h/unknown):
  • Warfarin: INR 2-3.
  • DOACs/LMWH: follow guidelines.
• Informed Consent: Obtained & documented.
• Equipment Check (SOAP-ME):
  • Suction, Oxygen source.
  • Airway cart (laryngoscope, ETT, LMA).
  • Pharmacy (emergency drugs: atropine, vasopressors).
  • Monitors (ECG, SpO2, NIBP, EtCO2).
  • Equipment (Defibrillator: functional, pads).

⭐ For elective cardioversion of AF >48h or unknown duration, anticoagulation for 3 weeks prior & 4 weeks post-procedure OR pre-procedure TEE is mandatory to prevent thromboembolism.

Anesthetic Goals & Drugs - Sweet Dreams, Steady Heart

• Key Goals:

  • Amnesia & analgesia (brief)
  • Brief akinesia for procedure
  • Maintain hemodynamic stability
  • Ensure rapid recovery & airway patency

• Oxygenation & Airway:

  • Preoxygenate: 100% O2; supplemental O2 (nasal cannula/mask).
  • Airway: Usually mask ventilation; LMA/ETT rare.

• Drug Options:

The Shocking Procedure & Aftercare - Zap & Nap Recovery

• Anesthetic Conduct:
  • Induction: IV Propofol (1-1.5 mg/kg), Etomidate (0.2-0.3 mg/kg). Maintain airway.
  • Monitoring: Standard ASA (ECG, NIBP, SpO2). EtCO2 if advanced airway.
• Procedural Steps:
  • Pre-oxygenate. Ensure deep sedation.
  • "All clear!" call before synchronized shock.
  • Assess rhythm & hemodynamics post-shock.
• Recovery:
  • Monitor: Vitals, LOC, oxygenation. Supplemental O2 if needed.
  • Pain relief for chest discomfort/burns (NSAIDs).
• Complications:
  • Arrhythmias: Bradycardia, asystole, VF.
  • Thromboembolism: CVA, PE (risk if poor anticoagulation).
  • Skin burns, muscle soreness, hypotension, respiratory depression, awareness (rare).

⭐ A common complication post-cardioversion is transient bradycardia or short sinus pauses; however, persistent asystole or Ventricular Fibrillation (VF) can occur, necessitating immediate Advanced Cardiac Life Support (ACLS).

High‑Yield Points - ⚡ Biggest Takeaways

• Cardioversion requires deep sedation/anesthesia for amnesia and patient comfort, ensuring rapid recovery.
• NPO guidelines are crucial; standard ASA monitoring (ECG, NIBP, SpO2, EtCO2) is mandatory.
• Airway management involves supplemental oxygen; keep airway adjuncts and intubation equipment ready.
• Propofol is preferred for its rapid onset/offset; Etomidate for hemodynamic stability.
• Key risks include aspiration and hemodynamic compromise; ensure adequate anticoagulation pre-procedure.
• Always confirm synchronization mode on the defibrillator before shock delivery_