Wolff-Parkinson-White (WPW) syndrome
Wolff-Parkinson-White syndrome is ventricular pre-excitation via an accessory pathway plus symptomatic tachyarrhythmia, marked on the resting ECG by a short PR interval and a delta wave. Its danger is pre-excited atrial fibrillation, which can conduct rapidly to the ventricles and degenerate into ventricular fibrillation; AV nodal blockers are contraindicated in that setting, and catheter ablation of the pathway is curative.
- Topic reviewThe full article, organized the way the exam asks it.
- ABIM-format MCQsVignettes with an explanation for every wrong answer.
- Key factsThe numbers and thresholds worth memorizing, up front.
- AI tutorMedBrain answers the question you're stuck on.
What this article covers
- Overview
Definition: Wolff-Parkinson-White (WPW) syndrome is the combination of an accessory atrioventricular pathway causing ventricular pre-excitation and symptomatic tachyarrhythmia; the pre-excitation…
- Epidemiology
Present from birth (a congenital accessory pathway), often diagnosed in young people.
- Risk factors
Congenital accessory pathway (bundle of Kent).
- Pathophysiology
Accessory pathway: an abnormal muscular connection bypasses the AV node, pre-exciting the ventricle and producing the delta wave.
- Clinical features
Palpitations from paroxysmal tachycardia (usually orthodromic AVRT).
- Differential diagnosis
AVNRT and other PSVT: regular narrow-complex tachycardia without a baseline delta wave (PSVT).
- Diagnosis
Establish with a resting ECG showing pre-excitation plus documented tachyarrhythmia: the diagnostic basis is a 12-lead ECG demonstrating a short PR interval (under 120 ms), a delta wave, and a…
- Management
First, treat by arrhythmia type and stability: Orthodromic AVRT (regular narrow-complex), stable: vagal maneuvers, then adenosine 6 mg then 12 mg by rapid IV push, each a single dose.
- Complications
Ventricular fibrillation and sudden cardiac death from pre-excited atrial fibrillation.
- Prognosis
Generally excellent, with cure after successful ablation.
- Prevention
Catheter ablation for symptomatic or high-risk pathways to prevent sudden death and recurrence.
Read the whole article
Subscribing to Internal Medicine opens every article, the full question bank and MedBrain, on the web, iPhone and Android.
Related articles
- Paroxysmal supraventricular tachycardia
Paroxysmal supraventricular tachycardia is a sudden-onset, regular narrow-complex tachycardia from a reentrant circuit involving the AV node (AVNRT) or an accessory pathway (AVRT), presenting with abrupt palpitations. Acute treatment is vagal maneuvers then adenosine, unstable patients receive synchronized cardioversion, and catheter ablation is a curative long-term option.
- Atrial fibrillation
Atrial fibrillation is a supraventricular tachyarrhythmia with disorganized atrial activation and an irregularly irregular ventricular response, the most common sustained arrhythmia and a major cause of stroke. Diagnosis is by ECG showing no discrete P waves with irregular RR intervals, and management addresses rate or rhythm control, stroke prevention by CHA2DS2-VASc-guided anticoagulation, and the underlying cause.
- Supraventricular tachycardia
Supraventricular tachycardia is any tachyarrhythmia arising at or above the AV node, usually a regular narrow-complex tachycardia. Acute management of a stable regular narrow-complex SVT is vagal maneuvers then adenosine; unstable patients receive synchronized cardioversion, and definitive therapy is catheter ablation.