WPW – Wolff-Parkinson-White Syndrome

Wolff-Parkinson-White (WPW) syndrome is a rare heart condition where there is an abnormal extra electrical pathway in the heart, which can lead to episodes of rapid heart rate (tachycardia). This extra pathway is present from birth and allows electrical signals to bypass the heart’s normal conduction system, causing abnormal heart rhythms, or arrhythmias.

Key Features of WPW:

  1. Extra Electrical Pathway (Accessory Pathway): In WPW, there is an additional connection between the atria (upper heart chambers) and the ventricles (lower heart chambers). This extra pathway allows electrical impulses to travel more quickly than usual, disrupting the normal rhythm of the heart.
  2. Supraventricular Tachycardia (SVT): The most common arrhythmia associated with WPW is a type of SVT, where the heart suddenly begins to beat very fast due to electrical signals travelling between the normal and extra pathways.

Symptoms

People with WPW may never experience symptoms. In fact, in the majority of people the extra pathway is completely silent. Palpitations are, however, the main symptom of WPW. Some people may find these palpitations untroubling, but in others they may cause chest pain, light-headedness and even blackouts. They may occur predictably or at any time and people may be able to control them. One way of doing this is by holding one’s breath as forcibly as possible. The palpitations may remain, however, until they can be stopped by an injection in an accident and emergency department.

Many individuals with WPW may not experience any symptoms, but when they do, these can include:

  • Rapid or irregular heartbeat (palpitations)
  • Dizziness or light-headedness
  • Shortness of breath
  • Chest pain or discomfort
  • Fainting (syncope)

In rare, severe cases, WPW can lead to life-threatening arrhythmias such as ventricular fibrillation.

How is Wolff (Wolfe)-Parkinson-White diagnosed?

WPW is typically diagnosed using an electrocardiogram (ECG), which shows characteristic features like a shortened PR interval and the presence of a delta wave (a slurred upstroke in the QRS complex). In some cases, an electrophysiology study (EPS) is conducted to confirm the diagnosis and locate the extra pathway. Other tests may include an ECHO, an exercise ECG and a 24-hour Holter monitor (tape).

If a person is a competitive athlete; or has a particular job such as a pilot or a soldier; or has had palpitations because of arrhythmia; more invasive tests (EP studies) may be recommended to assess the way the accessory pathway behaves and therefore the risk of significant arrhythmias.

Treatment of WPW

Treatment varies depending on the severity of symptoms and may include:

  • Observation: For asymptomatic individuals, immediate treatment may not be necessary, but regular monitoring is important.
  • Medications: Drugs such as beta-blockers or anti-arrhythmic medications may be used to control the heart rate and prevent episodes of tachycardia.
  • Catheter Ablation: This is the most effective and commonly used treatment for WPW. It involves threading a catheter through a blood vessel to the heart, where radiofrequency energy is used to destroy the extra electrical pathway.
  • Cardioversion: In cases of severe arrhythmia, cardioversion (an electric shock) may be used to restore a normal heart rhythm.

Although WPW can be a cause for concern, many individuals can lead normal, healthy lives with proper management and treatment.