Wolff-Parkinson-White Syndrome

Question 1

Definition

Answer 1

A congenital abnormality which can result in supraventricular tachycardias that use an accessory pathway. It is a pre-excitation syndrome.

Question 2

Aetiology/Risk factors

Answer 2

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

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

Question 3

Epidemiology

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

Presenting symptoms/Signs on physical examination

Answer 4

· SVT may occur in early childhood

· Often ASYMPTOMATIC - may be an incidental finding of an ECG

· Symptoms:
o Palpitations
o Light-headedness
o 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

Investigations

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:
o Short PR interval
o Broad QRS complex
o 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