Wolff-Parkinson-White Syndrome (WPW)

Wolff-Parkinson-White (WPW) syndrome is an abnormality of the heart’s electrical conduction system which can be associated with supraventricular tachycardia (SVT).

Wolff-Parkinson-White (WPW) syndrome is an abnormality of the heart's electrical conduction system which can be associated with supraventricular tachycardia (SVT). In WPW syndrome, there is an extra electrical pathway (called an "accessory pathway") in the heart which can transmit electrical impulses from the upper chambers (atria) to the lower chambers (ventricles) of the heart. In the normal conduction system, there is only one electrical conduction pathway from the atria to the ventricles. It is called the atrio-ventricular node (AV node). A WPW pathway bypasses the AV node and can transmit electrical signals through the heart faster than through the AV node This can cause SVT or other abnormal heart rhythms.

When impulses travel from the atria to the ventricles through the extra pathway, the ECG shows a pattern called a Delta wave or "pre-excitation". Each patient is different in how fast electrical impulses can be transmitted over this pathway. If the pathway is able to transmit very fast and if the patient has an arrhythmia known as atrial fibrillation (in which the atria pump from 300-600 times/minute), the extra pathway may transmit that very rapid rate.

Symptoms & Signs

Symptoms of Wolff-Parkinson-White syndrome are the result of a fast heart rate. Common symptoms of WPW syndrome include:

  • Sensation of rapid, fluttering, or pounding heartbeats (palpitations)
  • Dizziness
  • Chest discomfort
  • Difficulty breathing
  • Lightheadedness
  • Tiring easily during exercise
  • Anxiety

An episode of a very fast heartbeat can begin suddenly and last for a few seconds or even as long as several hours. Episodes often happen during exercise, but may also occur during quiet activities.

Some individuals with WPW syndrome occasionally experience a type of irregular heartbeat known as atrial fibrillation. In these individuals, WPW signs and symptoms may also include:

  • Chest pain
  • Chest tightness
  • Difficulty breathing
  • Fainting
  • Rarely, sudden death

Symptoms in infants with WPW syndrome may include:

  • Rapid or labored breathing
  • Lack of alertness or activity
  • Poor eating
  • Fast heartbeats visible on the chest

Most people who have an extra electrical pathway in the heart experience no fast heartbeat and no symptoms. This condition, called asymptomatic WPW, is usually discovered by chance when a person is undergoing a heart exam for other reasons. WPW pattern is harmless in many people. But doctors may recommend further evaluation before children with WPW patterns participate in high-intensity sports.  


WPW is discovered on the ECG (electrocardiogram). Information on ECGs are in the basic Electrophysiology fact sheet.

Some patients find out they have WPW because they had an ECG for another reason not related to their heart, such as a sports physical. Some patients are diagnosed after having an episode of SVT. The heart in patients with WPW may be built normally, or may be associated with structural abnormalities.

Finally, some patients find out they have WPW when they are admitted through the emergency department after having an episode of fainting or in rare occasions after cardiac arrest.


Treatment may include medication to prevent SVT. In babies, medication is given to prevent SVT for the first year. Up to 2/3 of babies will "outgrow" WPW when diagnosed at an early age (in the first year of life) and will not require further treatment.

The best way to determine if a patient is at risk for sudden death from their WPW pathway is an EP study.

Cardiac (heart) ablation has become the first line of treatment in older patients, especially in older children or adults.

Lifestyle Changes

Until a patient’s WPW has been fully evaluated, patients may have some restrictions on vigorous exercise, which is determined by the electrophysiologist or cardiologist caring for the patient.

Typically, if the extra pathway in WPW does not transmit very rapidly, then the patient does not have activity restrictions.

If a patient has a high-risk pathway that has not been ablated, he or she may be restricted from strenuous activities.

Keep Exploring

Heart Rhythm Disorders
Millions of people experience irregular or abnormal heartbeats, called arrhythmias, at some point in their lives. Most of the time, they are harmless and happen in healthy people free of heart disease. However, some abnormal heart rhythms can be serious or even deadly. Having other types of heart disease can also increase the risk of arrhythmias.
Pediatrics and Congenital Heart Disease (CHD)
This section is for pediatric patients and families living with heart rhythm disorders and heart rhythm disorders related to congenital heart disease (CHD).
Early Warning Signs
If you are experiencing a racing, pounding, rumbling or flopping feeling in your chest or if you have been fainting, having repeated dizzy spells, feeling lightheaded or you are extremely fatigued, it's time to see a doctor to discuss your heart health.
Common Treatments
Learning about the underlying cause of any heart rhythm disorder provides the basis for selecting the best treatment plan. Information and knowledge about care options, and their risks and benefits help you work with your health care provider to make the best choices.
Since other heart disorders increase the risk of developing abnormal heart rhythms, lifestyle changes often are recommended. Living a “heart healthy” lifestyle can ease the symptoms experienced with heart rhythm disorders and other heart disorders, and can be beneficial to overall patient health.
The Normal Heart
The heart is a fist-sized muscle that pumps blood through the body 24 hours a day, 365 days a year, without rest. The normal heart is made up of four parts: two atria on the top of the heart (right atrium and left atrium), and two ventricles (right ventricle and left ventricle) which are the muscular chambers on the bottom of the heart that provide the major power to pump blood.