Myocardial fibres extending from the atrium to the ipsilateral ventricle across the mitral or tricuspid annulus (accessory pathway) pre-excite the ventricle.
WPW syndrome is restricted to symptomatic patients with a typical ECG abnormality; WPW pattern signifies an asymptomatic patient with typical ECG abnormalities.
Patients often present with atrioventricular re-entrant tachycardia, less commonly atrial fibrillation, and, rarely, sudden cardiac death.
Asymptomatic patients can either be monitored or screened to determine whether they have a 'high-risk' accessory pathway, in which case catheter ablation is typically performed. Screening to determine whether a patient has a high-risk accessory pathway is recommended for patients who have high-risk occupations, such as school bus drivers or pilots, and also for competitive athletes. In patients with asymptomatic pre-excitation who have an accessory pathway demonstrating low risk features on invasive or non-invasive screening, an electrophysiology study and ablation can be considered.
Symptomatic patients usually undergo catheter ablation as first-line therapy. Pharmacological therapy can be considered for patients in whom catheter ablation fails and also for patients who prefer a non-invasive approach.
Catheter ablation is highly effective with low risk and can be used either as initial therapy or for patients experiencing side effects or arrhythmia recurrences despite medical treatment.
Occurs when one or more strands of myocardial fibres capable of conducting electrical impulses (known as accessory pathways [APs] or bypass tracts) connect the atrium to the ipsilateral ventricle across the mitral or tricuspid annulus. Conduction from the atrium reaches the adjacent ventricle earlier via the AP, and a part of the ventricle is pre-excited. The term 'Wolff-Parkinson-White (WPW) syndrome' is restricted to symptomatic patients with a typical ECG abnormality, whereas the term 'WPW pattern' signifies an asymptomatic patient with typical ECG abnormalities.
History and exam
Key diagnostic factors
- presence of risk factors
- atrioventricular re-entrant tachycardia (AVRT)
Other diagnostic factors
- shortness of breath
- chest pain
- atrial fibrillation
- atrial flutter
- congenital cardiac abnormalities
- sudden cardiac death
- syncope and presyncope
- tachycardia in pregnancy
- Ebstein's anomaly
- hypertrophic cardiomyopathy
- mitral valve prolapse
- atrial septal defect
- ventricular septal defect
- transposition of great vessels
- coarctation of aorta
- coronary sinus diverticula
- right and left atrial aneurysms
- cardiac rhabdomyomas
- Marfan's syndrome
- Friedreich's ataxia
- family history
1st investigations to order
- 12-lead ECG
Investigations to consider
- treadmill exercise test
- electrophysiology study
unstable: BP <90/60 mmHg, signs of systemic hypoperfusion or unstable atrial fibrillation
stable: narrow complex (orthodromic atrioventricular reciprocating) tachycardia
stable: wide complex (antidromic atrioventricular reciprocating) tachycardia
stable: pre-excited tachycardia due to atrial fibrillation or atrial flutter
stable: pre-excited tachycardia due to atrial tachycardia
following acute treatment: asymptomatic
following acute treatment: symptomatic
- Atriofascicular pathway
- Lown-Ganong-Levine syndrome
- Nodofascicular pathway
- European Resuscitation Council guidelines 2021
- 2017 AHA/ACC/HRS guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death
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