What are the guidelines for using beta (beta blockers) in patients with a history of Wolff-Parkinson-White (WPW) syndrome?

Beta Blocker Use in Patients with Wolff-Parkinson-White (WPW) Syndrome

Beta blockers are contraindicated in patients with WPW syndrome who have preexcited ventricular activation during atrial fibrillation (AF). 1

Risks of Beta Blockers in WPW

Beta blockers can be dangerous in patients with WPW syndrome for the following reasons:

• Beta blockers block the AV node, which can promote preferential conduction through the accessory pathway, potentially leading to life-threatening ventricular arrhythmias 1
• They are specifically contraindicated (Class III recommendation) in patients with WPW who have preexcited ventricular activation during AF 1
• Administration of beta blockers in patients with WPW and AF can accelerate the ventricular rate and potentially precipitate ventricular fibrillation 1

Management of Arrhythmias in WPW Patients

For Patients with WPW and Atrial Fibrillation:

• First-line treatment options:

  • Immediate direct-current cardioversion for hemodynamically unstable patients 1
  • Intravenous procainamide or ibutilide for hemodynamically stable patients 1
  • Catheter ablation of the accessory pathway is recommended for symptomatic patients, particularly those with syncope due to rapid heart rate 1

• Medications to avoid:

  • Beta blockers 1
  • Digitalis glycosides 1
  • Diltiazem or verapamil 1
  • Amiodarone (intravenous) 1
  • Adenosine 1

For Regular Supraventricular Tachycardia in WPW:

• In patients with WPW who have narrow-complex tachycardia (orthodromic AVRT) without preexcitation:
  • Beta blockers may be used cautiously if the mechanism is confirmed to be through the normal conduction system 2, 3
  • However, caution is still warranted as patients may develop AF during the episode

Special Considerations

• Approximately 25% of patients with WPW syndrome have accessory pathways with short anterograde refractory periods (<250 msec), which are associated with a risk of rapid ventricular rates and ventricular fibrillation 1
• The risk of developing AF over 10 years in patients with WPW syndrome is estimated at 15% 1
• Patients with multiple accessory pathways are at greater risk of ventricular fibrillation 1
• Catheter ablation of the accessory pathway is the definitive treatment for WPW syndrome, with high success rates and low complication rates 1, 3

Emergency Management of WPW with Rapid Arrhythmias

• For hemodynamically unstable patients: immediate electrical cardioversion 1
• For stable patients with wide-complex tachycardia or preexcited AF: IV procainamide or ibutilide 1
• Have defibrillator immediately available when treating these patients 4
• Avoid AV nodal blocking agents (beta blockers, calcium channel blockers, digoxin) 1, 5

Conclusion

Beta blockers should not be used in patients with WPW syndrome who have evidence of preexcitation, particularly during AF. The definitive treatment for symptomatic WPW syndrome is catheter ablation of the accessory pathway.