Slide 1: 20F w/ intermittent palpitations presents to clinic. [EKG] What is your dx?

Slide 2: Wolff-Parkinson-White Syndrome. *WPW pattern if EKG findings w/o symptomatic arrhythmias. [diagram of normal conduction, WPW accessory pathway (bundle of Kent), and conduction through the WPW pathway] EKG features: pre-excitation of ventricular tissue causes slurring of QRS takeoff (delta wave), PR<120ms, QRS>120ms.

Slide 3: Commonly associated arrhythmias: AV reentrant tachycardia (AVRT). Up to 80% of patients with WPW have AVRT, a reentrant circuit that develops with conduction through both the AV node and the accessory pathway. Stable patients who develop this subset of supraventricular tachycardia CAN undergo vagal maneuvers, AV nodal blockade.

Slide 4: Commonly associated arrhythmias: atrial fibrillation. 15-30% of patients with WPW have concurrent atrial fibrillation (AF). Patients with WPW who develop AF with rapid ventricular response should NOT receive AV nodal blockade, as this will promote conduction via the accessory pathway and degeneration into ventricular fibrillation. Treatment instead should be with procainamide.