QuestionSBA
QuestionChoice
Pulmonary vein ablation (PVA) is a treatment for symptomatic atrial fibrillation (AF). The area where tissue from the atrium and pulmonary veins meet is the source of ectopic atrial depolarisation that drives AF. PVA aims to destroy this area of tissue using radiofrequency energy or cryoablation
32274
b
Referral for pulmonary vein ablation
QuestionChoice
Flecainide can be used in WPW in patients who are not suitable for or who refuse accessory pathway ablation
32275
c
Flecainide
QuestionChoice
Digoxin is an AV nodal blocking agent and should be avoided in WPW as it may precipitate conduction down the accessory pathway and thereby trigger an arrhythmia
32277
e
Digoxin
QuestionChoice
This patient has a history and ECG findings consistent with symptomatic Wolff-Parkinson-White (WPW) syndrome. This is a condition in which there is a congenital accessory pathway through which there can be aberrant conduction and pre-excitation of the ventricles.

Key ECG findings are a short PR interval and a broad QRS complex with a slurred upstroke (known as a delta wave).

Definitive management is a referral to an electrophysiologist for ablation of the accessory pathway
32273
a
Referral for accessory pathway ablation
QuestionChoice
Verapamil is an AV nodal blocking agent and should be avoided in WPW as it may precipitate conduction down the accessory pathway and thereby trigger an arrhythmia
32276
d
Verapamil
Concept
Chapter
# Summary

Wolff-Parkinson-White (WPW) syndrome is a congenital pre-excitation syndrome characterised by the presence of an abnormal accessory electrical pathway between the atria and ventricles. This pathway predisposes individuals to arrhythmias, including supraventricular tachycardias (SVTs) that can potentially lead to ventricular fibrillation. Diagnosis is based on electrocardiogram (ECG) findings such as delta waves, short PR interval, and broadened QRS complex. Management options include conservative monitoring, medical treatment with anti-arrhythmics, and definitive treatment through radiofrequency ablation of the accessory pathway. Emergency management of tachyarrhythmias in WPW syndrome varies based on patient stability and the specific rhythm present. Successful ablation has a high cure rate of 95%.

# Definition 

WPW syndrome is a congenital pre-excitation syndrome that occurs due to the presence of an accessory electrical pathway between the atria and ventricles. It predisposes patients to supraventricular tachycardias, specifically an AVRT. 

# Epidemiology 

The prevalence of WPW syndrome is approximately 100-300 per 100,000 people. Men are more commonly affected than women, with the ratio being approximately 2 to 1. 

# Classification 

WPW syndrome can be classified as Type A or Type B dependent on where the aberrant pathway is. 

Type A 

* Pathway between the left atrium and ventricle. 

Type B 

* Pathway between the right atrium and ventricle. 


# Symptoms and Signs

Patients may present with:

* No symptoms - WPW is often asymptomatic
* Palpitations
* Dizziness
* Syncope

There are often no signs on examination unless the patient is currently experiencing a paroxysmal episode of SVT. 

# Investigations

## Bedside

**1st line = ECG** 

* Delta waves (slurred upstroke in the QRS) 
* Short PR interval (<120ms) 
* Broadened QRS complex 
* If a re-entrant circuit has developed the ECG will show a narrow complex tachycardia. 

[lightgallery]

If a patient is experiencing paroxysmal symptoms a 24 hour tape may be used for continuous monitoring. 

## Bloods 

Routine bloods including TFTs should be completed to investigate non-cardiac causes of tachycardia. 

## Imaging

* Echocardiogram: to assess for structural cardiac disease and to assess ventricular function. 
* Cardiac catheterisation - electrophysiological studies can help map the location of the accessory pathway and identify a focus for ablation. 

# Long-Term Management

## Conservative 

WPW syndrome may just be monitored if asymptomatic. The majority of patients identified with ECG findings of pre-excitation do not develop tachyarrhythmias. 

## Medical 

Anti-arrhythmics may be used if a patient is having paroxysmal SVT. Medications include amiodarone and sotalol. These are contraindicated in structural heart disease. 

**Contraindications in WPW**: medications that block the AVN are contraindicated in WPW. If you block the AVN, more electrical activity is conducted down the accessory pathway prediposing to dangerous arrhythmias. Digoxin, adenosine, and non-dihydropyridine calcium-channel blockers (verapamil and diltiazem) are therefore contraindicated. 

## Interventional and Surgical 

Definitive management of WPW syndrome is radiofrequency ablation of the accessory pathway. Rarely, surgical (open heart) ablation can be performed in complex cases. 

# Emergency Management

**If a patient with WPW presents with a tachyarrhythmia manage as follows:** 

*If there are adverse signs (e.g. shock, syncope, heart failure, myocardial ischaemia):*

* **1st line** = **synchronised DC cardioversion**

*If the patient is stable they are managed according to the rhythm:*

* In WPW patients with a narrow complex tachycardia with a short PR interval management is as per SVT management guidelines. 
	* **1st line = vagal manouevres:** Valsalva manouevre or carotid sinus massage. 
	* **2nd line = adenosine**

* In WPW patients with a broad complex tachycardia, atrial fibrillation, or atrial flutter
	* **1st line = IV anti-arrhythmics:** procainamide or fleicanide as they help prevent rapid conduction through the accessory pathway. 
	* **2nd line = DC cardioversion**

# Complications

Due to the accessory pathway in WPW, if a patient develops atrial fibrillation this can pass to ventricles, bypassing the AVN, and causing ventricular fibrillation and cardiac arrest. 

# Prognosis 

It is estimated that there is a 95% success rate if WPW syndrome is treated with ablation. If radiofrequency ablation is successful, the WPW is considered cured. 

# NICE Guidelines

[NICE Guidance on Palpitations](<https://cks.nice.org.uk/topics/palpitations/diagnosis/assessment/#:~:text=Wolff%2DParkinson%2DWhite%20(WPW)%20syndrome.&text=Slight%20widening%20of%20the%20QRS,syndrome%20can%20cause%20paroxysmal%20tachycardia.>)

# References 

[Patient UK Information on WPW Syndrome](<https://patient.info/doctor/wolff-parkinson-white-syndrome-pro>)
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Picture
Prominent delta waves in V4-V6 in someone with WPW syndrome.
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634
Wolff-Parkinson-White syndrome
Topic
35
Cardiology
6455
Wolff-Parkinson-White (WPW) syndrome is characterized by an abnormal extra electrical pathway in the heart, leading to episodes of rapid heart rate. Referral for accessory pathway ablation is recommended for patients with symptomatic WPW or those at risk of serious arrhythmias
A 23-year-old man presents to his General Practitioner (GP) with two brief episodes of syncope that were preceded by palpitations. He was admitted the previous year with palpitations which were found to be due to supraventricular tachycardia (SVT) that responded to initial management with vagal manoeuvres.

Clinical examination is unremarkable and his observations are normal. An ECG shows a short PR interval and a widespread slurred upstroke on the QRS complexes.

Which of the following is the best step in management?
a