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

Management of Wolff-Parkinson-White Syndrome

Catheter ablation of the accessory pathway is the first-line treatment for symptomatic patients with Wolff-Parkinson-White syndrome, particularly those with syncope due to rapid heart rate or those with a short bypass tract refractory period. 1, 2

Initial Management Based on Clinical Presentation

Hemodynamically Unstable Patients

• Immediate direct-current cardioversion is recommended for patients with pre-excited AF and hemodynamic compromise to prevent ventricular fibrillation 2
• Have resuscitation equipment readily available as patients with WPW and rapid ventricular response have high risk of developing ventricular fibrillation 3

Hemodynamically Stable Patients

• For patients with pre-excited AF without hemodynamic compromise and wide QRS complex (≥120 ms), intravenous procainamide or ibutilide is recommended to restore sinus rhythm 2
• Alternative medications for stable patients include intravenous quinidine, disopyramide, or amiodarone (Class IIb recommendation) 2
• For acute management of narrow QRS complex tachycardias (indicating conduction through AV node), IV adenosine may be used 3, 4

Critical Medication Considerations

• AVOID AV nodal blocking agents in patients with pre-excited AF as they can accelerate conduction through the accessory pathway and precipitate ventricular fibrillation 2
• Specifically contraindicated medications include:
  • Digoxin 2, 5
  • Diltiazem 2, 5
  • Verapamil 2, 5
  • Beta-blockers 2
  • Adenosine (when QRS is wide) 3, 4

Definitive Management

• Catheter ablation of the accessory pathway is recommended for all symptomatic patients with WPW syndrome 2, 1
• Ablation has a success rate >95% with a complication rate (permanent AV block) of <1-2% in experienced centers 1
• Specific indications for catheter ablation include:
  • Symptomatic tachycardias 1, 6
  • Syncope due to rapid heart rate 2
  • Short bypass tract refractory period (<250 ms) 2, 1
  • Pre-excited atrial fibrillation 2, 1

Risk Assessment

• High-risk features that warrant more aggressive management include:
  • Shortest pre-excited R-R interval <250 ms during spontaneous or induced atrial fibrillation 1, 4
  • History of symptomatic tachycardia or syncope 1, 4
  • Multiple accessory pathways 1, 4
  • Associated structural heart disease 4

Special Considerations

• Ablation of the accessory pathway does not always prevent AF, especially in older patients, and additional pharmacological therapy may be required 2, 1
• Approximately one-third of patients with WPW syndrome may develop atrial fibrillation, which can degenerate into ventricular fibrillation 1
• The annual risk of sudden cardiac death is estimated at 0.15-0.2% in general WPW patients, but higher (2.2%) in symptomatic patients 1
• For asymptomatic patients with incidental WPW pattern on ECG, risk stratification through electrophysiological study may be useful to determine management approach 4, 6

Pitfalls to Avoid

• Never administer AV nodal blocking agents (digoxin, diltiazem, verapamil) in patients with pre-excited AF as they can accelerate the ventricular rate and potentially precipitate ventricular fibrillation 2, 3
• Don't delay cardioversion in patients with hemodynamic compromise 2
• Avoid type IC antiarrhythmic drugs in patients with AF in the setting of acute myocardial infarction 2
• Don't assume that catheter ablation will prevent all future arrhythmias; post-ablation monitoring is necessary 2, 1