Wolff-Parkinson-White syndrome can involve episodes of rapid heart rate (tachycardia) and usually has an abnormal baseline ECG caused by extra electrical pathways (circuits) in the heart.

Normally, electrical signals in the heart go through a pathway that helps the heart beat regularly. The wiring of the heart prevents extra beats from occurring and keeps the next beat from happening too soon.

In people with Wolff-Parkinson-White syndrome, there is an extra, or accessory, pathway that may cause a very rapid heart rate (supraventricular tachycardia).

Wolff-Parkinson-White is one of the most common causes of fast heart rate disorders (tachyarrhythmias) in infants and children.

How often the rapid heart rate occurs depends on the patient. Some people with Wolff-Parkinson-White syndrome may have just a few episodes of rapid heart rate. Others may experience the rapid heart rate once or twice a week. Sometimes the patient has no symptoms. In these cases, the extra pathway is often found when a doctor has requested an ECG for some other purpose.

A person with WPW syndrome may have:

• Palpitations (a sensation of feeling your heart beat)
• Light-headedness
• Fainting
• Dizziness
• Shortness of breath
• Chest pain or chest tightness

An exam performed during a tachycardia episode will reveal a heart rate greater than 230 beats per minute and blood pressure that is normal or low. A normal heart rate is 60 - 100 beats per minute in adults, and under 150 beats per minute in neonates, infants, and small children.

If the patient is currently not having tachycardia, the physical exam may be completely normal. Wolff-Parkinson-White syndrome may be revealed by the following tests:

• ECG (electrocardiogram) may show an abnormality called a "delta" wave.
• Continuous ambulatory monitoring (Holter monitor).
• EPS, an intracardiac electrophysiologic study, may help identify the location of the extra electrical pathway in Wolf-Parkinson-White syndrome.

The goal of treatment is to reduce symptoms by reducing the episodes of tachycardia (rapid heart rate).

Medication may be used to control or prevent rapid heart beating. These include adenosine, antiarrhythmics, and amiodarone. Digoxin, verapamil, and beta-blockers (other drugs commonly used to treat other types of tachycardia) can increase the frequency of tachycardia episodes for some people with Wolff-Parkinson-White.

To end a spell of tachycardia (fast heart rate) that will not stop with medicines, doctors may use electrical cardioversion (shock).

In catheter ablation, a catheter (tube) inserted into an artery through a small cut near your groin, to reach the heart. When the tip reaches the heart, the small area that is causing the fast heart rate is destroyed using a special type of energy called radiofrequency. The success rate for this procedure ranges between 85 - 95%. It is currently the preferred therapeutic approach to treat Wolff-Parkinson-White syndrome in the United States.

Open heart surgery may also provide a permanent cure for Wolff-Parkinson-White syndrome. However, most patients typically have catheter ablation. Surgery is usually done only if the patient must have surgery for other reasons.

While the outcome varies, the success rate is very high. Using a catheter to deliver radiofrequency waves to destroy the abnormal pathway usually cures Wolff-Parkinson-White.

• Reduced blood pressure (caused by continous rapid heart rate)
• Heart failure
• Side effects of medications
• Complications of surgery

The most severe form of tachyarrhythmia is atrial fibrillation. It may rapidly lead to shock, and  requires emergency treatment (cardioversion).

Olgin JE, Zipes DP. Specific arrhythmias: Diagnosis and treatment. Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. St. Louis, Mo: WB Saunders; 2007. http://www.mdconsult.com/about/book/83821525-2/instruct.html?DOCID=1549. Accessed December 11, 2007.