Wolff-Parkinson-White syndrome (WPW) is most common in children who are born with a heart condition (congenital heart disease), but it can also occur in those without.
In the UK, between 1 and 3 people in every 1,000 are thought to have WPW syndrome
Most people experience symptoms between the ages of 30 and 40.
WPW syndrome is a condition that makes the heart suddenly beat abnormally fast, in an abnormal heart rhythm called supraventricular tachycardia (SVT).
Episodes can last for seconds, minutes, hours or, in rare cases, days.
The frequency with which episodes occur can vary from person to person. Some people might have episodes on a daily basis, whereas others may only experience them occasionally.
Children with the syndrome will often report having symptoms such as:
- chest pain
- difficulty breathing
Adults often experience symptoms such as a:
- pounding heartbeat that occurs suddenly
- pulse that's too fast to count
- reduced ability to tolerate activity
In rare cases of WPW syndrome, a person's heart rate can increase significantly when a heart rhythm called atrial fibrillation occurs. The combination of the syndrome and atrial fibrillation can be life threatening and requires emergency assessment.
When the heart beats normally, its muscular walls contract (tighten and squeeze) to force blood out and around the body. They then relax, allowing the heart to fill with blood again.
In WPW syndrome, electrical signals in the heart can travel round and round in a loop, causing the heart to beat very fast. The heart muscle contracts at such a fast rate that it has very little time to relax and fill with blood inbetween contractions.
This reduces the amount of blood being pumped around the body, which can give the symptoms of dizzy or light-headedness, shortness of breath, and faintness or fainting.
If a person known to have WPW syndrome collapses or faints then this is an emergency, which requires a 999 ambulance call.
Someone with the syndrome may have heart palpitations, where the heart feels like it's pounding, fluttering or beating irregularly for a few seconds or minutes. They may not experience heart palpitations, and the syndrome may only be picked up if they have an electrocardiogram (ECG) for another reason.