Wolff-Parkinson-White Syndrome: An Uncommon Cause of Palpitations

Palpitations are a common presenting symptom in the emergency department (ED). Typically, the cause of palpitations is benign, especially in otherwise young, healthy patients. For example, premature atrial contractions, infrequent premature ventricular contractions, and sinus tachycardia may be caused by anxiety, stress, and excessive intake of stimulants such as caffeine. However, clinicians must be aware of and alert for more serious underlying conditions. In this article, we report the case of a young man who presented with palpitations and a wide complex tachycardia on electrocardiogram (ECG). The patient’s symptoms were caused by atrial fibrillation with a rapid ventricular response due to underlying WolffParkinson-White (WPW) syndrome. WPW syndrome, which is classified among the paroxysmal supraventricular tachycardias (PSVTs), is a relatively uncommon cardiac conduction disorder that occasionally may cause early excitation (preexcitation) of the ventricles due to antegrade atrioventricular (AV) conduction through an accessory pathway. Patients with WPW syndrome may present with preexcited atrial fibrillation. ECG tracings of patients who have WPW syndrome typically reveal a narrow QRS complex, but WPW syndrome associated with preexcited atrial fibrillation may produce a wide QRS complex on ECG. These ECG findings are commonly confused with other causes of wide QRS complex tachycardia, such as ventricular tachycardia. Atrial fibrillation can lead to congestive heart failure (CHF), cardiogenic shock, and even sudden cardiac death unless it is correctly and expeditiously diagnosed and treated. In patients with WPW syndrome, prompt recognition of the underlying mechanism is essential so that appropriate therapy targeting the accessory pathway can be initiated. This article highlights the challenges of diagnosing preexcited atrial fibrillation and reviews its acute management as well as discusses important causes of PSVT.