Heart and Blood Conditions
What is Wolff-Parkinson-White syndrome?
Wolff-Parkinson-White (WPW) is a condition in which the heart has an extra electrical pathway, also called an accessory pathway. Because of this extra pathway, electrical signals in the heart bypass the normal electrical pathway.
The heart has 4 chambers that work like a pump. The atria are the 2 top chambers. They receive blood from the lungs and the rest of the body. The ventricles are the 2 bottom chambers. They pump blood out to the lungs and the rest of the body. It is important for all 4 chambers of the heart to work together with one another to create an effective pump.
A group of cells called the sinus node is located at the top of the right atrium. This is known as the “pacemaker” of the heart. It works to control the normal heart rate. It makes the heart beat slower during times of rest or sleep and beat faster with exercise, fear or excitement.
Each heartbeat begins with an electrical wave (signal) that passes from the sinus node through the atria. This signal travels through the atria much like the ripples created in water when a pebble is thrown in. This electrical signal makes the atria contract, or squeeze, making them beat.
Next, the electrical signal moves from the atria into the junction between the atria and ventricles. This junction is known as the atrioventricular node (AV node). The AV node delays the signal slightly and then passes it on to the ventricles, making them beat. Normally, the only way for signals to pass from atria to the ventricles is through the AV node.
After the ventricles beat, the heartbeat cycle is complete. The next heartbeat starts in the sinus node and follows the same path. In children with WPW, electrical signals in the heart do not travel along the normal route because they have an extra (accessory) pathway.
WPW may lead to 2 kinds of heart rhythm problems:
- Supraventricular tachycardia (SVT). Tachycardia (pronounced tack-ih-CARD-ee-ah) means the heart is beating too fast. SVT may require treatment. It is not usually life threatening.
- Atrial fibrillation leading to ventricular fibrillation. Fibrillation (pronounced fib-rill-AY-shun) means very fast, irregular twitching of a muscle. Atrial fibrillation is rare in children. When it happens to someone without WPW, the normal route of electricity in the heart slows signals from the atria to the ventricles. This limits how quickly the ventricles beat. When it happens to someone with WPW, the accessory pathway can move fast, irregular signals from the atria directly to the ventricles. This can cause ventricular fibrillation, which is life threatening. This heart rhythm problem may need to be reset using a defibrillator.
In WPW, the extra (accessory) pathway is typically present at birth. Some children with WPW begin having symptoms shortly after birth or in early childhood. Other children with WPW may never have symptoms or develop them later in childhood or even as adults.
About 10% to 20% of infants with WPW also have congenital heart disease, usually Ebstein’s anomaly.
Wolff-Parkinson-White Syndrome at Seattle Children’s
U.S. News & World Report consistently ranks Seattle Children’s cardiology and heart surgery program as one of the best in the country. With more than 40 pediatric cardiologists, we have experience diagnosing and treating every kind of heart problem.
Our heart team has treated many children with WPW syndrome. We have years of experience providing the treatment these children may require through our Arrhythmia Program. Some children do not require any treatment, but many will have treatment to cure their WPW syndrome.
The Arrhythmia Program provides a full range of services for treating heart rhythm problems, including:
- Radiofrequency ablation and cryoablation
- Pacemaker or defibrillator implantation
In many cases, we can provide treatment for WPW with minimal or zero-radiation ablation. We also have a pediatric cardiac anesthesia team and a Cardiac Intensive Care Unit to help care for children who undergo heart surgery.
The Adult Congenital Heart Disease Program shared by Seattle Children’s and the University of Washington can help with care throughout your child’s life.
Seattle Children’s has been treating children since 1907. Our team members are experts in their fields and in meeting the unique needs of children. For example, the doctors who give your child anesthesia (sedation) are board certified in pediatric anesthesiology. This means they have extra years of training in how to take care of kids. Our child life specialists know how to help children understand their illnesses and treatments in ways that make sense for their age.
When you come to Seattle Children’s, a team of people will take care of your child. Along with your child’s heart doctor (cardiologist), you are connected with other providers, such as neonatologists, lung doctors (pulmonologists), nurses, child life specialists, social workers and others, if their expertise is needed.
We work together to meet all of your child’s health needs and help your family through this experience. We’ll discuss treatments in ways you can understand and involve you in every decision.
Read more about the supportive care we offer.
Symptoms of Wolff-Parkinson-White Syndrome
WPW syndrome can cause these problems with your child’s heartbeat:
- Their heart beats too quickly (tachycardia, pronounced tack-ih-CARD-ee-ah).
- Their heartbeat is irregular — the speed and pattern change.
- They have palpitations.
You and your child may or may not notice any of these problems with their heartbeat. Sometimes, families have no idea their child has WPW syndrome until it’s noticed during a regular check-up or when the child has an electrocardiogram (ECG) for some other reason.
Because the heartbeat affects blood flow, arrhythmias can sometimes cause these symptoms:
- Feeling faint, weak, lightheaded or dizzy
- Being short of breath
- Having chest pain
- Fainting (syncope)
Diagnosing Wolff-Parkinson-White Syndrome
To diagnose WPW syndrome, your doctor will examine your child, check their heartbeat and use a stethoscope to listen to their heart. The doctor will ask for details about any symptoms your child has, their health history and your family health history.
Some children with this condition have periods of arrhythmia, or a racing heart rate, only once in a while. This sometimes makes the condition hard to diagnose. To learn about the electrical activity in your child’s heart, the doctor will use an electrocardiogram (ECG).
If an abnormal heartbeat does not happen during this test, your child may need to wear a portable ECG device for a while. A device called a Holter monitor can record their heart’s activity for 24 hours. Another device called an event record can be turned on by your child when they feel a problem with their heart rhythm.
To get more information about how your child’s heart looks and works, the doctor may do other tests, such as exercise testing and electrophysiology studies, to help identify the location of the extra electrical pathway in your child’s heart. They may also need chest X-rays or MRI (magnetic resonance imaging) of the heart, angiography and echocardiography.
Treating Wolff-Parkinson-White Syndrome
Your child may not need any treatment for WPW syndrome. Often, an irregular heartbeat does not cause any problems. But sometimes it keeps the heart from pumping the right amount of blood to the brain or other organs. This can be dangerous.
So it’s important to have WPW syndrome checked by a doctor who can offer treatment if your child needs it.
Your child may need treatment if they have symptoms or they have a fast heartbeat that happens often or lasts for a while.
Doctors treat WPW syndrome first with medicines to control the heart rate. If medicine does not work well enough, doctors may use radiofrequency ablation. This is a procedure that uses a catheter to destroy the tissue that causes the fast heartbeat.
Read more about the treatment options we offer through our Arrhythmia Program.
Contact the Heart Center at 206-987-2515 to request an appointment, a second opinion or more information.
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