What is the heart's normal condition?
In a normal heart, electrical signals use only one path when they move through the heart. This is the atrio-ventricular or A-V node. As the electrical signal moves from the heart's upper chambers (the atria) to the lower chambers (the ventricles), it causes the heart to beat. For the heart to beat properly, the timing of the electrical signal is important.
What is the Wolff-Parkinson-White syndrome?
If there's an extra conduction pathway, the electrical signal may arrive at the ventricles too soon. This condition is called Wolff-Parkinson-White syndrome (WPW). It's in a category of electrical abnormalities called "pre-excitation syndromes."
It's recognized by certain changes on the electrocardiogram, which is a graphical record of the heart's electrical activity. The ECG will show that an extra pathway or shortcut exists from the atria to the ventricles.
Many people with this syndrome who have symptoms or episodes of tachycardia (rapid heart rhythm) may have dizziness, chest palpitations, fainting or, rarely, cardiac arrest. Other people with WPW never have tachycardia or other symptoms. About 80 percent of people with symptoms first have them between the ages of 11 and 50.
How is this syndrome treated?
People without symptoms usually don't need treatment. People with episodes of tachycardia can often be treated with medication. But sometimes such treatment doesn't work. Then they'll need to have more tests of their heart's electrical system.
The most common procedure used to interrupt the abnormal pathway is radiofrequency or catheter ablation. In this, a flexible tube called a catheter is guided to the place where the problem exists. Then that tissue is destroyed with radiofrequency energy, stopping the electrical pathway. Successful ablation ends the need for medication. Whether a person will be treated with medication or with an ablation procedure depends on several factors. These include the severity and frequency of symptoms, risk for future arrhythmias and patient preference.