Wolff-Parkinson-White Syndrome

You have been told you have Wolff-Parkinson-White (WPW) Syndrome. WPW can lead to extremely rapid heart rates. These arrhythmias, or abnormal heart rhythms, can produce symptoms such as palpitations, light-headedness, or even loss of consciousness. In rare instances, WPW can lead to cardiac arrest.

The heart, which is a muscle, has an electrical system which is responsible for causing it to contract and relax. Normally, each heart beat begins in the SA node. The SA node is a group of cells located in the upper right chamber of the heart. An electrical impulse travels from the SA node and spreads across both upper chambers, or the atria. The atria then contract. The impulse next travels to the AV node, located between the upper and lower chambers of the heart. From here, the impulse leaves the AV node and spreads down and across both lower chambers, or the ventricles. The ventricles contract, pumping blood to the body.

However, in WPW, an extra electrical pathway exists between the atria and the ventricles. This extra pathway may at times encourage a rapid rhythm. Instead of allowing the next heart beat to begin at the SA node, the extra pathway can "pick up" an electrical impulse in the ventricles and send it abnormally back upward to the atria. When this happens, the impulse begins to travel abnormally in a rapid, circular manner, causing a rapid heart rate.

This pattern can stop on its own or can require medical interventions to end the arrhythmia.

Your doctor may be able to tell you that you have WPW based on your EKG. Sometimes, an electrophysiology (EP) study is necessary to determine the presence of the extra pathway.

Treatment
Treatment of WPW is based on the severity of symptoms experienced with the rapid heart rates. Medications may be able to control the occurrence of any rapid heart rates. However, some people are not able to tolerate these medications. In addition, very fast heart rates and severe symptoms (such as loss of consciousness) may persist despite the use of medications. A procedure known as catheter ablation can be used to destroy the abnormal pathway, and prevent the rapid heart rates associated with the abnormal pathway. Please refer to the sections on EP study and catheter ablation for further information on these procedures.