The effect of ibutilide on retrograde accessory pathway conduction

Area of Science:

• Cardiology
• Electrophysiology

Background:

• Atrial fibrillation and flutter are common arrhythmias.
• Concealed accessory pathways can cause symptomatic atrioventricular reentry tachycardia.
• Ibutilide is a Class III antiarrhythmic agent known for converting atrial arrhythmias.

Observation:

• Three patients with symptomatic atrioventricular reentry tachycardia and concealed accessory pathways experienced recurrent atrial fibrillation.
• Intravenous ibutilide (1-2 mg) was administered during electrophysiological evaluation.
• Retrograde accessory pathway conduction was monitored.

Findings:

• Ibutilide successfully converted atrial fibrillation to sinus rhythm in all three patients.
• Sinus rhythm was maintained throughout the electrophysiological procedures.
• Retrograde accessory pathway conduction remained unchanged by ibutilide.
• Successful mapping and catheter ablation of concealed accessory pathways were achieved without direct current cardioversion.

Implications:

• Ibutilide is effective in managing atrial fibrillation induced by atrioventricular reentry tachycardia in patients with concealed accessory pathways.
• It facilitates successful catheter ablation by maintaining sinus rhythm without masking retrograde pathway conduction.
• Further studies are needed to assess antegrade accessory pathway conduction effects.