What is the management of Wolff-Parkinson-White (WPW) syndrome?

Management of Wolff-Parkinson-White (WPW) Syndrome

Catheter ablation of the accessory pathway is the definitive treatment of choice for all symptomatic patients with Wolff-Parkinson-White syndrome, especially those with risk factors for sudden cardiac death. 1

Risk Stratification

Risk assessment is crucial in WPW management as it guides treatment decisions:

High-Risk Features (Indications for Urgent Catheter Ablation)

• Short accessory pathway refractory period (<250 ms)
• Multiple accessory pathways
• History of pre-excited atrial fibrillation
• Presence of Ebstein's anomaly
• History of syncope 1

Acute Management of WPW with Arrhythmias

For Pre-excited Atrial Fibrillation (Hemodynamically Unstable)

• Immediate direct-current cardioversion (Class I recommendation) 1

For Pre-excited Atrial Fibrillation (Hemodynamically Stable)

1. IV procainamide (first-line medication, Class I recommendation)
2. IV ibutilide (alternative first-line, Class I recommendation) 1
3. Alternative options (Class IIb recommendation):
   • IV quinidine
   • IV disopyramide
   • IV amiodarone (use with caution) 1

Critical Medication Contraindications

AVOID THE FOLLOWING MEDICATIONS in patients with WPW syndrome, especially during atrial fibrillation (Class III: Harm recommendation):

• AV nodal blocking agents:
  • Beta-blockers
  • Non-dihydropyridine calcium channel blockers (verapamil, diltiazem)
  • Digoxin 1, 2

These medications can accelerate conduction through the accessory pathway and precipitate ventricular fibrillation by blocking the normal AV nodal pathway while leaving the accessory pathway unaffected. 1

Long-term Management

First-line Treatment

• Catheter ablation of the accessory pathway (success rates >95% with experienced operators) 1

Pharmacological Options (When Ablation is Delayed or Contraindicated)

• Class IC antiarrhythmics (flecainide, propafenone) can be effective by slowing conduction through the accessory pathway 1, 3
• Amiodarone may be considered in select cases until definitive treatment 1

Propafenone specifically reduces conduction and increases the effective refractory period of the accessory pathway in both directions in WPW syndrome 3, making it a reasonable pharmacological option when ablation is not immediately available.

Special Populations

Pregnant Patients with WPW

• Direct-current cardioversion for hemodynamically unstable patients
• Multidisciplinary approach involving cardiology, obstetrics, and anesthesiology
• Vaginal delivery is preferred in hemodynamically stable patients
• Consider early cesarean delivery if ventricular function deteriorates or arrhythmias become difficult to control 1

Follow-up and Monitoring

For patients with WPW who have not undergone ablation:

• ECG evaluation at 3 months and annually during the first years
• Patient education about symptoms requiring immediate medical attention
• Continuous cardiac monitoring during and after conversion of arrhythmias 1

Important Caveats

1. Risk of sudden death: The risk ranges from 0.15% to 0.6% per year, with highest risk in the first two decades of life 1

2. Medication pitfalls: Beta-blockers like propranolol are specifically contraindicated in WPW syndrome with tachycardia and can cause severe bradycardia requiring pacemaker treatment 2

3. ECG misdiagnosis: WPW pattern can mimic inferior myocardial infarction; careful identification of delta waves is essential 4

4. Emergency department awareness: Pre-excited atrial fibrillation must be correctly identified to avoid administration of AV nodal blocking agents that could precipitate ventricular fibrillation 5