Wolff–Parkinson–White syndrome

Question 1

Define WPW syndrome

Answer 1

A congenital abnormality which can result in supraventricular tachycardias that use an accessory pathway.

It is a pre-excitation syndrome.

Question 2

Explain the aetiology/risk factors of WPW syndrome

Answer 2

The accessory pathway (bundle of Kent) is likely to be congenital

Associations:
Congenital cardiac defects
Ebstein's anomaly (congenital malformation of the heart characterised by displacement of septal and posterior tricuspid leaflets)
Mitral valve prolapse
Cardiomyopathies (e.g. HOCM)

Question 3

Summarise the epidemiology of WPW syndrome

Answer 3

Relatively COMMON

Most common of the ventricular pre-excitation syndromes

Found in ALL AGES

More common in the YOUNG

Prevalence decreases with age

Question 4

Recognise the presenting symptoms and signs of WPW syndrome

Answer 4

SVT may occur in early childhood

Often ASYMPTOMATIC - may be an incidental finding of an ECG

Symptoms:
Palpitations
Light-headedness
Syncope
Paroxysmal SVT may be followed by a period of
polyuria, due to atrial dilatation and release of ANP
Sudden death - if SVT deteriorates into VF

Clinical features of associated cardiac defects (e.g. mitral valve prolapse, cardiomyopathy)

Question 5

Identify appropriate investigations for WPW syndrome

Answer 5

ECG may be normal if the conduction speed of the impulse along the accessory pathway matches the conduction speed down the bundle of His

Classic ECG findings:
Short PR interval
Broad QRS complex
Slurred upstroke producing a delta wave
Patient may be in SVT (AVRT)

Bloods - check for other causes of arrhythmia

Echocardiogram - check for structural heart defects