What is the recommended treatment for Wolff-Parkinson-White (WPW) syndrome?

Management of Wolff-Parkinson-White (WPW) Syndrome

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

Acute Management of WPW with Atrial Fibrillation

Hemodynamically Unstable Patients

• Immediate direct-current cardioversion is recommended to prevent ventricular fibrillation in patients with a short anterograde bypass tract refractory period who develop AF with rapid ventricular response causing hemodynamic instability 2, 1
• Start with 100 J and increase in a stepwise fashion if needed 1

Hemodynamically Stable Patients

• Intravenous procainamide or ibutilide is recommended to restore sinus rhythm in patients with WPW and AF without hemodynamic instability when there is a wide QRS complex (≥120 ms) or rapid preexcited ventricular response 2, 1
• Intravenous flecainide or direct-current cardioversion is reasonable when very rapid ventricular rates occur 2
• It may be reasonable to administer intravenous quinidine, procainamide, disopyramide, ibutilide, or amiodarone to hemodynamically stable patients 2

Medications to Avoid

• AV nodal blocking agents are contraindicated in patients with WPW and AF:
  • Digoxin
  • Non-dihydropyridine calcium channel antagonists (diltiazem, verapamil)
  • Beta-blockers
  • Adenosine
  • These medications can accelerate ventricular rate by preferential conduction through the accessory pathway 2, 1, 3

Definitive Treatment

Catheter Ablation

• First-line therapy for symptomatic WPW syndrome 1, 4
• Success rates >95% with low complication rates 1, 5
• Particularly indicated for:
  • Patients with pre-excited atrial fibrillation
  • Patients with syncope due to rapid heart rate
  • Patients with accessory pathways with short refractory periods (<250 ms) 1
• Overall complication rate is approximately 2.5% 6
  • Higher risk with septal pathway location (9.1% vs 2.0% for left-sided) 6
  • Higher risk for repeat procedures (6.9% vs 2.2% for first-time) 6
• Recurrence rate is approximately 9.7%, with prior antiarrhythmic medication use associated with higher recurrence rates 6

Risk Stratification

• High-risk features include:
  • Shortest pre-excited R-R interval <250 ms during AF
  • History of symptomatic tachycardia
  • Multiple accessory pathways
  • Ebstein's anomaly 1

Asymptomatic WPW

• Invasive electrophysiological study and possible ablation may be considered for:
  • Professional reasons (pilots, athletes, heavy machinery operators)
  • Patients willing to accept a small procedural risk to eliminate the very small risk of sudden death 1, 4

Post-Ablation Care

• ECG assessment at 3 months post-procedure and annually for the first few years 1
• Patient education on symptoms warranting immediate medical attention 1
• Approximately 5-10% of patients may experience recurrence of accessory pathway conduction 1
• Ablation does not always prevent atrial fibrillation, especially in older patients 1
• A second ablation procedure is typically successful if WPW syndrome recurs 6, 7

Pitfalls and Caveats

• Never use AV nodal blocking agents (digoxin, calcium channel blockers, beta-blockers, adenosine) in patients with suspected WPW and AF, as they can accelerate conduction through the accessory pathway and precipitate ventricular fibrillation 2, 1
• Multiple or large accessory pathways may require specialized approaches 7
• Epicardial accessory pathways may require irrigated-tip catheters 7
• Posteroseptal accessory pathways may require bi-atrial and coronary sinus applications 7
• For parahisian and midseptal accessory pathways, careful titration of radiofrequency energy is crucial 7