In Wolff-Parkinson-White syndrome, there is an extra electrical pathway in the heart — an abnormal bridge of heart muscle fibers that connects the upper chambers of the heart to the lower chambers. This extra pathway may allow electrical impulses to travel rapidly in the heart, causing an abnormally fast heartbeat, a form of supraventricular tachycardia. The extra electrical pathway may be seen on an electrocardiogram (EKG or ECG), causing an abnormal pattern known as a delta wave. In rare cases, the heart rhythm can be extremely rapid and potentially dangerous.
The "normal" number of heartbeats per minute, called pulse rate, varies with age. The heart beats about 140 times a minute in a newborn, compared to 70 times a minute in an older child at rest. Heart rate is not constant, changing in response to many factors, such as activity, fever and fear. With Wolff-Parkinson-White syndrome, the heart beats too quickly — up to 300 beats per minute. The heart cannot fill completely with blood, preventing the body from receiving the blood volume it needs to function properly.
Wolff-Parkinson-White syndrome may cause the following symptoms:
It is important to note that during an episode of Wolff-Parkinson-White syndrome, children may not know how to describe what they are feeling. They may have trouble keeping up with other children or realize they are having "spells" and want to sit down and rest. Sometimes, children do not experience any symptoms at all.
Wolff-Parkinson-White syndrome may occur spontaneously with unpredictable timing. Therefore, specialized tests may be needed to make an accurate diagnosis. If your doctor suspects that your child has an arrhythmia caused by Wolff-Parkinson-White syndrome, he or she may order one or more of the following diagnostic tests:
Treatment for Wolff-Parkinson-White syndrome will depend on the type and severity of your child's condition and the results of the diagnostic tests, such as the electrophysiology (EP) study. You and your child's doctor will decide which treatment is right for your child.
The following treatments may be considered:
Certain anti-arrhythmic drugs change the electrical signals in the heart and help prevent irregular or rapid heart rhythms from occurring. Medication may be used to convert the arrhythmia of Wolff-Parkinson-White syndrome to a normal rhythm, slow down the heart rate or prevent recurrences.
Reviewed by health care specialists at UCSF Benioff Children's Hospital.
Last updated
July 12, 2010
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