Wolff Parkinson White syndrome

Question 1

What is Wolff Parkinson White syndrome?

Answer 1

Congenital accessory conducting pathway between atria + ventricles leading to AVRT
Pre-excitation syndrome.

Question 2

What is a pre-excitation syndrome?

Answer 2

early activation of the ventricles due to impulses bypassing the AV node via an accessory pathway.

Question 3

Describe the aetiology of Wolff Parkinson White syndrome

Answer 3

Accessory pathway (bundle of Kent) is likely to be congenital

Question 4

List 5 associations of Wolff Parkinson White syndrome

Answer 4

HOCM
Mitral valve prolapse
Ebstein’s anomaly (congenital)
Thyrotoxicosis
Secundum ASD

Question 5

Describe the epidemiology of Wolff Parkinson White syndrome

Answer 5

Relatively COMMON  
Most common of the ventricular pre-excitation syndromes  
Found in ALL AGES  
YOUNG > OLD
Prevalence decreases with age

Question 6

Give 2 symptoms of Wolff Parkinson White syndrome

Answer 6

Palpitations

Light-headedness

Question 7

Give 3 signs of Wolff Parkinson White syndrome

Answer 7

Paroxysmal SVT may be followed by a period of polyuria, due to atrial dilatation + release of ANP
Syncope
Clinical features of associated cardiac defects (e.g. mitral valve prolapse, cardiomyopathy)

Question 8

Describe ECG findings in Wolff Parkinson White syndrome

Answer 8

ECG may be normal if the conduction speed of the impulse along the accessory pathway matches the conduction speed down the bundle of His.
Patient may be in SVT (AVRT)

Question 9

What are the classic ECG signs of Wolff Parkinson White syndrome?

Answer 9

Short PR interval
Broad QRS complex with
slurred upstroke ‘delta wave’
LAD if right sided accessory pathway (majority of cases)
RAD if left sided accessory pathway

Question 10

How can you differentiate between type A and type B WPW syndrome?

Answer 10

Type A (left sided pathway): dominant R wave in V1

Type B (right sided pathway): no dominant R wave in V1

Question 11

What investigations may be performed in Wolff Parkinson White syndrome?

Answer 11

Bloods: identify other causes of arrhythmia
Treadmill exercise test
Echo

Question 12

What structural heart defects may be found on echo in Wolff Parkinson White syndrome? (associated risk 7-20%)

Answer 12

Coronary artery disease  
Cardiomyopathy  
Valvular heart disease  
Long QT syndrome  
Brugada syndrome

Question 13

How may Wolff Parkinson White be diagnosed?

Answer 13

SVT may occur in early childhood
Often ASYMPTOMATIC; may be an incidental finding of an ECG

Question 14

Why is Wolff-Parkinson-White syndrome dangerous?

Answer 14

May lead to sudden death if SVT deteriorates into VF

Question 15

What medical therapy can be given in WPW syndrome?

Answer 15

Sotalol
Amiodarone
Flecainide

Question 16

When should sotalol be avoided in WPW syndrome?

Answer 16

If coexistent atrial fibrillation
Prolonging the refractory period at the AVN may increase rate of transmission through the accessory pathway, increasing ventricular rate + potentially deteriorating into VF

Question 17

What is the definitive treatment of WPW syndrome?

Answer 17

Radiofrequency ablation of the accessory pathway