What is the treatment for Wolff-Parkinson-White (WPW) emergent tachycardia?

Treatment of WPW Emergent Tachycardia

Immediate synchronized electrical cardioversion is the first-line treatment for hemodynamically unstable patients with WPW syndrome presenting with emergent tachycardia, regardless of the type of tachycardia. 1

Initial Assessment and Management

Hemodynamically Unstable Patients

• Immediate synchronized cardioversion is required when very rapid tachycardias or hemodynamic instability occurs in patients with AF involving conduction over an accessory pathway 2, 1
• Have defibrillation equipment immediately available and maintain ECG monitoring during treatment 1

Hemodynamically Stable Patients

For stable patients, follow this algorithm:

1. First-line: Vagal maneuvers (Valsalva maneuver) 1

2. Second-line: If pre-excited atrial fibrillation is NOT suspected:

   • Adenosine administration (3 mg rapid IV bolus, followed by 6 mg and then 12 mg if needed) 1
   • Note: For adenosine, a defibrillator should be available when administered to any patient in whom WPW is a consideration 2

3. Third-line: If adenosine fails:

   • IV procainamide or ibutilide to restore sinus rhythm 2, 1
   • Synchronized cardioversion if medications fail 1

Critical Caution

• NEVER administer AV nodal blocking agents (diltiazem, beta-blockers, digoxin, adenosine, verapamil) to patients with WPW and suspected pre-excited atrial fibrillation 2, 1
• These medications can accelerate conduction through the accessory pathway, potentially precipitating ventricular fibrillation 1
• This contraindication is a Class III: Harm recommendation with Level of Evidence: B 1

Pharmacological Management for Pre-excited AF in WPW

• First choice: IV procainamide or ibutilide 2, 1
• Alternative: Intravenous quinidine, disopyramide, or amiodarone for hemodynamically stable patients with AF involving conduction over an accessory pathway 2
• Contraindicated: Amiodarone in patients with WPW syndrome who have pre-excited AF (Class III: Harm recommendation, Level of Evidence: B) 1

Post-Acute Management

• Catheter ablation is recommended for symptomatic patients with WPW syndrome, particularly those with:

  • Syncope due to rapid heart rate
  • Accessory pathways with short refractory periods (<250 ms)
  • Multiple accessory pathways 1

• Success rates for catheter ablation exceed 95%, with significant improvement in quality of life 1

High-Risk Features Requiring More Aggressive Management

• Short refractory period of accessory pathway (<250 ms)
• Multiple accessory pathways
• History of pre-excited atrial fibrillation
• Associated cardiac anomalies (e.g., Ebstein's anomaly) 1

Follow-Up Considerations

• Regular cardiac monitoring and risk reassessment are essential
• ECG evaluation at 3 months and annually during the first years
• Patient education about symptoms requiring immediate medical attention 1

Remember that the incidence of sudden death in patients with WPW syndrome varies from 0 to 0.6% per year, with high-risk patients having short anterograde refractory periods (<250 ms) and short R-R intervals during pre-excited atrial fibrillation 2, 1.