Atrial flutter with 1:1 conduction in undiagnosed Wolff-Parkinson-White syndrome.
BACKGROUND
Atrial flutter with 1:1 atrioventricular conduction via an accessory pathway is an uncommon presentation of Wolff-Parkinson-White syndrome not previously reported in the emergency medicine literature. Wolff-Parkinson-White syndrome, a form of ventricular preexcitation sometimes initially seen and diagnosed in the emergency department (ED), can present with varied tachydysrhythmias for which certain treatments are contraindicated. For instance, atrial fibrillation with preexcited conduction needs specific consideration of medication choice to avoid potential degeneration into ventricular fibrillation.


METHODS
We describe an adult female presenting with a very rapid, regular wide complex tachycardia successfully cardioverted in the ED followed by a normal electrocardiogram (ECG). Electrophysiology study confirmed atrial flutter with 1:1 conduction and revealed an accessory pathway consistent with Wolff-Parkinson-White syndrome, despite lack of ECG findings of preexcitation during sinus rhythm. Why should an emergency physician be aware of this? Ventricular tachycardia must be the first consideration in patients with regular wide complex tachycardia. However, clinicians should consider atrial flutter with 1:1 conduction related to an accessory pathway when treating patients with the triad of very rapid rate (>250 beats/min), wide QRS complex, and regular rhythm, especially when considering pharmacologic treatment. Emergency physicians also should be aware of electrocardiographically concealed accessory pathways, and that lack of delta waves does not rule out preexcitation syndromes such as Wolff-Parkinson-White syndrome.
Emergency Medicine Department, Regions Hospital, St. Paul, Minnesota; Department of Emergency Medicine, University of Minnesota, Minneapolis, Minnesota.
Jessie G
JG
Nelson
Cardiac Electrophysiology Laboratories, Regions Hospital, St. Paul, Minnesota; Department of Medicine, University of Minnesota, Minneapolis, Minnesota.
Dennis W
DW
Zhu
D001282:Atrial Flutter / Q000175:diagnosis* / Q000503:physiopathology; D003937:Diagnosis, Differential; D004554:Electric Countershock; D005260:Female; D006801:Humans; D008875:Middle Aged; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000503:physiopathology; D016896:Treatment Outcome; D014927:Wolff-Parkinson-White Syndrome / Q000175:diagnosis* / Q000503:physiopathology
Wolff-Parkinson-White syndrome; accessory pathway; atrial flutter; preexcitation; wide complex tachycardia