[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Conditions](https://durgical.com/en/conditions/) › Wolff-Parkinson-White syndrome [Conditions](https://durgical.com/en/conditions/) · [Cardiology](https://durgical.com/en/conditions/) # Wolff-Parkinson-White syndrome In WPW an extra electrical bridge links the upper and lower heart chambers. It can cause bursts of fast heartbeat and, rarely, sudden death. Updated 2026-11-01 ## Structures involved Tap one to see what it is and open it in 3D. - [Atrioventricular (AV) node](https://durgical.com/en/anatomy/atrioventricular-node/) - [Right atrium](https://durgical.com/en/anatomy/right-atrium/) - [Left ventricle](https://durgical.com/en/anatomy/left-ventricle/) - [Left atrium](https://durgical.com/en/anatomy/left-atrium/) - [Bundle of His](https://durgical.com/en/anatomy/atrioventricular-bundle/) - [Right ventricle](https://durgical.com/en/anatomy/right-ventricle/) - [Mitral anterior leaflet](https://durgical.com/en/anatomy/anterior-leaflet-of-left-atrioventricular-valve/) - [Tricuspid septal leaflet](https://durgical.com/en/anatomy/septal-leaflet-of-right-atrioventricular-valve/) ## In embryology - [Ebstein anomaly](https://durgical.com/en/embryology/ebstein-anomaly/) - [Lithium and Ebstein anomaly](https://durgical.com/en/embryology/lithium-and-ebstein-anomaly/) ## Why it happens - [The cardiac conduction system](https://durgical.com/en/physiology/the-cardiac-conduction-system/) - [How arrhythmias arise](https://durgical.com/en/physiology/how-arrhythmias-arise/) - [ECG basics: waves, intervals and leads](https://durgical.com/en/physiology/ecg-basics-waves-intervals-and-leads/) ## What it is A congenital accessory pathway (bundle of Kent) connects atrium and ventricle outside the [atrioventricular node](https://durgical.com/en/anatomy/atrioventricular-node/). The ECG shows ventricular pre-excitation, and the syndrome is defined by pre-excitation together with episodes of tachycardia. ## Who gets it Pre-excitation is found in roughly 1 to 3 per 1,000 people; many never have symptoms. It is a common cause of tachycardia in children and young adults. It is often detected on ECGs done for sports screening, school medical exams or before surgery. ## Causes - Persistence of muscular connections between atria and ventricles that normally disappear during fetal development - Mostly sporadic; a minority are familial - Association with congenital heart disease, especially Ebstein anomaly, and with some cardiomyopathies ## Risk factors - Ebstein anomaly and other congenital heart disease - Family history of pre-excitation - Multiple accessory pathways or a pathway with a short refractory period (higher risk of sudden death) ## Pathophysiology The accessory pathway conducts faster than the atrioventricular node, so part of the ventricle is activated early: short PR interval and a slurred QRS upstroke (delta wave). The pathway and the node form a circuit for re-entry. In orthodromic atrioventricular re-entrant tachycardia (the most common), the impulse goes down the node and back up the pathway, giving a narrow QRS. If atrial fibrillation develops, a pathway with fast conduction can transmit very high rates to the ventricles and degenerate into ventricular fibrillation. ## Classification - WPW pattern: pre-excitation on the ECG without symptoms - WPW syndrome: pre-excitation plus tachycardia episodes - Orthodromic atrioventricular re-entrant tachycardia (narrow QRS) and antidromic (wide QRS) - Pre-excited atrial fibrillation (irregular, wide and varying QRS) - By pathway location: left free wall (most common), posteroseptal, right free wall, anteroseptal ## Symptoms and signs - Sudden-onset and sudden-offset palpitations - Dizziness, [chest](https://durgical.com/en/anatomy/region/chest/) discomfort or dyspnoea during episodes - Syncope - Sudden cardiac arrest as the first event, rarely - Often asymptomatic, found on a routine ECG ## Red flags - Syncope or palpitations with a very fast, irregular, wide-complex tachycardia (pre-excited atrial fibrillation) - Haemodynamic instability during tachycardia - Resuscitated cardiac arrest in a young person ## Diagnosis **Clinical** Suspect it in a young person with recurrent episodes of paroxysmal palpitations, or when the ECG shows pre-excitation. **Tests** Resting 12-lead ECG: short PR interval, delta wave and wide QRS with secondary ST-T changes. ECG during an episode, Holter or event monitor, and exercise testing (abrupt loss of pre-excitation suggests a lower-risk pathway). An electrophysiological study maps the pathway, assesses risk and allows ablation in the same session. **Imaging** Echocardiography to look for structural heart disease such as Ebstein anomaly or hypertrophic cardiomyopathy. ## Differential diagnosis - Atrioventricular nodal re-entrant tachycardia - Atrial fibrillation with bundle branch block - Ventricular tachycardia - Lown-Ganong-Levine pattern or other short-PR variants - Hypertrophic cardiomyopathy with ECG abnormalities ## Goal of treatment Terminate acute episodes safely, avoid drugs that block the atrioventricular node in pre-excited atrial fibrillation, and eliminate the accessory pathway with ablation in symptomatic or high-risk patients. ## Treatment **Acute** Unstable patient (any tachycardia): synchronised electrical cardioversion. **Acute** Stable orthodromic narrow-complex tachycardia: vagal manoeuvres, then adenosine or other atrioventricular nodal blockers, with a defibrillator available. **Acute** Pre-excited atrial fibrillation: cardioversion or procainamide (or ibutilide); avoid adenosine, beta-blockers, non-dihydropyridine calcium channel blockers, digoxin and intravenous amiodarone, which can speed conduction over the pathway and cause ventricular fibrillation. **Procedure** Catheter ablation of the accessory pathway: first-line definitive treatment for symptomatic patients and high-risk asymptomatic ones, with a high cure rate. **Follow-up** Nursing priorities: continuous ECG monitoring during episodes, defibrillator at the bedside when giving drugs, blood pressure checks and education to recognise and report episodes. ## Complications - Pre-excited atrial fibrillation degenerating into ventricular fibrillation - Sudden cardiac death - Tachycardia-induced cardiomyopathy with frequent long episodes - Rare complications of ablation (atrioventricular block, vascular injury, tamponade) ## Prognosis Excellent after successful ablation, which cures most patients. The risk of sudden death is low overall but real, especially with a fast-conducting pathway, which is why risk assessment is recommended even in asymptomatic people with high-risk occupations or sports. ## Prevention - Pre-participation ECG screening where available and evaluation of young people with palpitations or syncope - Electrophysiological risk assessment of asymptomatic pre-excitation in selected patients ## Test yourself Think of the answer, then tap the question to see it. ## Which three ECG findings define pre-excitation in WPW? Short PR interval, delta wave (slurred QRS upstroke) and wide QRS. ## What is the most common tachycardia in WPW syndrome? Orthodromic atrioventricular re-entrant tachycardia, with a narrow QRS (down the node, up the pathway). ## Which drugs must be avoided in pre-excited atrial fibrillation, and why? Atrioventricular nodal blockers such as adenosine, beta-blockers, verapamil or diltiazem, and digoxin, because they favour conduction down the accessory pathway and can cause ventricular fibrillation. ## Which drug or intervention is preferred for stable pre-excited atrial fibrillation? Procainamide (or ibutilide); synchronised cardioversion if unstable. ## Which congenital heart defect is classically associated with WPW? Ebstein anomaly of the tricuspid valve. [Add to my cards (5)](https://durgical.app/estudiar/?add=/en/conditions/wolff-parkinson-white-syndrome/) ## Related conditions - [Supraventricular tachycardia (AVNRT, AVRT)](https://durgical.com/en/conditions/supraventricular-tachycardia/) - [Atrial fibrillation](https://durgical.com/en/conditions/atrial-fibrillation/) - [Cardiac arrest (VF, pulseless VT, asystole, PEA)](https://durgical.com/en/conditions/cardiac-arrest/) - [Ventricular tachycardia](https://durgical.com/en/conditions/ventricular-tachycardia/) - [Hypertrophic cardiomyopathy](https://durgical.com/en/conditions/hypertrophic-cardiomyopathy/) - [Ebstein anomaly](https://durgical.com/en/conditions/ebstein-anomaly/) - [Syncope (vasovagal, orthostatic hypotension, cardiac)](https://durgical.com/en/conditions/syncope/) Educational information, not medical advice. For any symptom, see a health professional. Sources: [Wolff-Parkinson-White syndrome (WPW): MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000151.htm) (MedlinePlus, US National Library of Medicine, 2026). [← All conditions](https://durgical.com/en/conditions/) ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/conditions/wolff-parkinson-white-syndrome/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/conditions/wolff-parkinson-white-syndrome/