Wolff-Parkinson-White Syndrome

What is Wolff-Parkinson-White Syndrome?

Wolff-Parkinson-White (WPW) syndrome is a condition in which there is an extra electrical connection between the upper chambers of the heart (the atria) and the lower chambers of the heart (the ventricles).

Normally, electrical signals use only one pathway (the atrioventricular or A-V node) when they move through the heart between the atria and ventricles. As the electrical signal moves through the lower chambers, it causes the heart to beat. The electrical signal must be coordinated in order for the heart to contract (beat) properly.

In WPW, the extra electrical connection between the upper and lower chambers may cause a short circuit. With this short circuit, the heart beats very quickly. Instead of its normal rate of 70 to 80 beats a minute, it may beat over 200 times a minute (tachycardia).

How does it occur?

This extra pathway is present at birth. No one knows what causes it. It may cause symptoms as early as the first year of life or as late as age 60.

What are the symptoms?

Most of the time, people with WPW have no symptoms. When supraventricular tachycardia (SVT) develops, however, the most common symptom is palpitations. You may feel your heart pounding rapidly in your chest. Sometimes you feel the pounding in your throat or neck. Sometimes the heart may beat so fast that you get dizzy or lightheaded or may even pass out.

In general, WPW syndrome is not life-threatening. However, you may develop atrial fibrillation (the upper part of your heart beats or quivers faster than the rest of your heart). The heart may be forced to beat so rapidly that it stops pumping completely. Fortunately, this situation is quite rare.

How is it diagnosed?

You will have an electrocardiogram (ECG) to measure the electrical activity of your heart. If a distinctive pattern shows on your ECG, and you have SVT, you will be diagnosed with WPW syndrome. If this distinctive pattern does not show on the ECG, you may need an electrophysiology study (EPS). EPS tests the condition of your heart's conduction system by measuring the speed of an electrical impulse traveling through the system. It locates conduction pathways that are in the wrong place.

Some people with WPW syndrome may be asked to have an echocardiogram. This test shows the structural health of the heart and its valves.

How is it treated?

People with no symptoms, or whose symptoms are short-lived, usually don't need treatment. Fast or irregular heartbeats can often be treated with medicine. But sometimes medicine doesn't work. You may need cardioversion, for which you are sedated and then a brief electrical shock to the chest is used to get the heart rhythm back to normal.

If you have severe and frequent symptoms, you may have a procedure known as radiofrequency ablation. In this procedure, a flexible tube called a catheter is placed in the heart through a vein or artery in the groin. The catheter is guided to the extra pathway. The extra pathway is cauterized (destroyed) with a low energy electrical current.

With proper treatment, your heart may beat in a healthy rhythm, and you may resume a more normal lifestyle.