Wolff-Parkinson-White (WPW) syndrome

Overview

In Wolff-Parkinson-White (WPW) syndrome, an extra signaling pathway between the heart's upper and lower chambers causes a fast heartbeat (tachycardia). WPW syndrome is a heart condition present at birth (congenital heart defect). It is fairly rare.

The episodes of fast heartbeats seen in WPW syndrome usually aren't life-threatening, but serious heart problems can occur. Rarely, WPW syndrome may lead to sudden cardiac death in children and young adults.

Treatment of WPW syndrome may include special actions, medications, a shock to the heart (cardioversion) or a catheter procedure to stop the irregular heart rhythm (arrhythmia).

WPW syndrome may also be called preexcitation syndrome.

Symptoms

The most common sign of Wolff-Parkinson-White (WPW) syndrome is a heart rate greater than 100 beats a minute.

Episodes of a fast heart rate (tachycardia) can begin suddenly and may last a few seconds or several hours. Episodes can occur during exercise or while at rest.

Other signs and symptoms of WPW syndrome are related to the fast heart rate and underlying heart rhythm problem (arrhythmia). The most common arrhythmia seen with WPW syndrome is supraventricular tachycardia. Supraventricular tachycardia causes episodes of a fast, pounding heartbeat that begin and end abruptly. Some people with WPW syndrome also have a fast and chaotic heart rhythm problem called atrial fibrillation.

In general, signs and symptoms that may occur in people with WPW syndrome include:

• A rapid, fluttering or pounding heartbeat (palpitations)
• Chest pain
• Difficulty breathing
• Dizziness or lightheadedness
• Fainting
• Fatigue
• Shortness of breath
• Anxiety

Symptoms in infants

Signs and symptoms of WPW syndrome in infants can include:

• Pale or faded skin color (pallor)
• Blue or gray coloring to the skin, lips and nails (cyanosis)
• Restlessness or irritability
• Rapid breathing
• Poor eating

Some people with an extra electrical pathway don't have signs or symptoms of a fast heartbeat. This condition is called Wolff-Parkinson-White (WPW) pattern. It's often discovered by chance during a heart test.

When to see a doctor

Many things can cause a fast heartbeat. It's important to get a prompt diagnosis and care. Sometimes a fast heartbeat, or heart rate, isn't a concern. For example, the heart rate may increase with exercise.

If you feel like your heart is beating too fast, make an appointment to see a health care provider.

Call 911 or your local emergency number if you have any of the following symptoms for more than a few minutes:

• Sensation of a fast or pounding heartbeat
• Difficulty breathing
• Chest pain

Causes

Wolff-Parkinson-White (WPW) syndrome is a type of heart problem present at birth (congenital heart defect). WPW syndrome may occur with other types of congenital heart disease, such as Ebstein anomaly.

Rarely, WPW syndrome is passed down through families (inherited). The inherited, or familial, type is associated with a thickened heart muscle. This is a form of hypertrophic cardiomyopathy.

To understand the causes of WPW syndrome, it may be helpful to know how the heart typically beats.

How does the heart beat?

The heart is made of four chambers — two upper chambers (atria) and two lower chambers (ventricles).

The heart's rhythm is controlled by a natural pacemaker (the sinus node) in the right upper chamber (atrium). The sinus node sends electrical signals that typically start each heartbeat. These electrical signals move across the atria, causing the heart muscles to squeeze (contract) and pump blood into the ventricles.

Next, the heart signals arrive at a cluster of cells called the AV node, where the signals slow down. This slight delay allows the ventricles to fill with blood. When the electrical signals reach the ventricles, the chambers contract and pump blood to the lungs or to the rest of the body.

In a typical heart, this heart signaling process usually goes smoothly, resulting in a resting heart rate of 60 to 100 beats a minute.

In WPW syndrome, an extra electrical pathway connects the upper and lower heart chambers, allowing heart signals to bypass the AV node. As a result, the heart signals don't slow down. The signals become excited, and the heart rate gets faster. The extra pathway can also cause heart signals to travel backward, causing an uncoordinated heart rhythm.

Complications

WPW syndrome has been linked to sudden cardiac death in children and young adults.