Wolff-Parkinson-White syndrome

Definition

Wolff-Parkinson-White syndrome is a heart condition in which there is an extra electrical pathway (circuit) in the heart. The condition can lead to episodes of rapid heart rate (tachycardia).

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

Alternative Names

Preexcitation syndrome; WPW

Causes, incidence, and risk factors

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. This is called supraventricular tachycardia.

Symptoms

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 have the rapid heart rate once or twice a week. Sometimes there are no symptoms, and the condition is detected when a heart tests are done for another reason.

A person with WPW syndrome may have:

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

Signs and tests

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.

A test called EPS may help identify the location of the extra electrical pathway.

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)

Treatment

Medication may be used to control or prevent rapid heart beating. These include adenosine, antiarrhythmics, and amiodarone.

If the heart rate does not return to normal with medication, doctors may use a type of therapy called electrical cardioversion (shock).

The current preferred therapy for Wolff-Parkinson-White syndrome is catheter ablation. This procedure involves inserting a tube (catheter) into an artery through a small cut near the groin up to the heart area. 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.

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

Expectations (prognosis)

Catheter ablation cures this disorder in most patients. The success rate for the procedure ranges between 85 - 95%.

Complications

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

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

Calling your health care provider

Call your health care provider if symptoms of Wolff-Parkinson-White develop, or if you have this disorder and symptoms get worse or do not improve with treatment.

References

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:chap 35.