A case of atrial fibrillation with preexcitation and duodromic tachycardia

Orthodromic atrioventricular reentrant tachycardia (AVRT), where the atrioventricular (AV) node serves as the anterograde limb and accessory pathway serves as the retrograde limb, is the most common type of arrhythmia in patients with Wolff Parkinson White (WPW) syndrome. Antidromic AVRT, where the accessory pathway serves as the anterograde limb and the AV node serves as the retrograde limb, is far less common—having been clinically documented in less than 5% patients with WPW syndrome and found to be inducible in less than 10% of cases patients with WPW undergoing electrophysiology (EP) study1.