According to the 2025 AHA guidelines, what joules are recommended for cardioversion of ventricular tachycardia (stable, unstable, and pulseless)?

VT Cardioversion Energy Recommendations per 2025 AHA Guidelines

For synchronized cardioversion of ventricular tachycardia with a pulse (stable or unstable), refer to your specific device's recommended energy level to maximize first shock success; if not known, use the maximum energy setting 1.

Energy Dosing by Clinical Scenario

Unstable VT with Pulse (Monomorphic or Polymorphic)

• Immediate synchronized cardioversion is warranted when the patient shows signs of instability (hypotension with systolic BP <80 mm Hg or altered mentation) 1
• The 2025 guidelines have moved away from specific joule recommendations, instead directing clinicians to:
  • Use device-specific manufacturer recommendations for optimal energy settings
  • If manufacturer settings are unknown, use maximum energy setting 1
• This represents a shift from incremental energy approaches to prioritizing first-shock success

Pulseless VT (Cardiac Arrest)

• Treat identically to ventricular fibrillation with immediate defibrillation (unsynchronized)
• Use biphasic defibrillator when available (preferred over monophasic) 1
• Energy approach options:
  • Fixed energy settings OR escalating energy settings - both are highly effective 1
  • When manufacturer-specified setting is unknown, apply maximum dose setting for that device 1
  • One randomized trial showed fixed 150 J vs. escalating 200-300-360 J had similar first-shock success, though escalating energy improved organized rhythm conversion in patients requiring multiple shocks (without survival difference) 1

Polymorphic VT (Sustained)

• All adult patients with sustained polymorphic VT receive immediate defibrillation (COR 1, LOE B-NR) 2
• This is a key 2025 update: previous guidelines suggested multiple treatment modalities based on stability, but sustained polymorphic VT now mandates immediate defibrillation regardless of apparent stability
• Medical treatments (magnesium for torsades with long QT) should not delay defibrillation 2

Critical Pitfalls to Avoid

Do not use low initial energy settings for unstable patients: The 2025 guidelines specifically moved away from incremental approaches. Starting at maximum or device-recommended energy reduces:

• Duration of arrhythmia exposure
• Risk of inducing VF with suboptimal shocks
• Cumulative electrical burden
• Anesthesia duration (if applicable) 2

Do not delay cardioversion for medication administration in unstable VT: Immediate electrical therapy takes priority 1

Do not confuse synchronized cardioversion (for VT with pulse) with unsynchronized defibrillation (for pulseless VT/VF): Using synchronized mode on pulseless VT delays shock delivery and worsens outcomes

Practical Algorithm

1. Assess pulse and stability

   • No pulse → Unsynchronized defibrillation (pulseless VT protocol)
   • Pulse present → Proceed to step 2

2. Assess hemodynamic stability

   • Unstable (SBP <80, altered mentation, shock, chest pain, acute heart failure) → Immediate synchronized cardioversion
   • Stable monomorphic VT → Consider adenosine or vagal maneuvers first, then cardioversion if persistent 1

3. Select energy setting

   • Check device manufacturer recommendation
   • If unknown: Use maximum energy setting 1

4. Ensure synchronized mode (for patients with pulse)

5. Sedate if time permits and patient stable enough

The 2025 guidelines emphasize that device-specific optimization trumps arbitrary joule recommendations, reflecting recognition that biphasic waveform characteristics vary between manufacturers and optimal energy differs accordingly 1.