What Is Wolff-Parkinson-White Syndrome?
Wolff-Parkinson-White syndrome is a birth defect in which the heart develops an extra electrical pathway, which can lead to a rapid heart rate (tachycardia). Medications may help alleviate the symptoms. However, a surgical procedure called catheter ablation is usually used to destroy the extra pathway and restore normal heart rhythm.
What Causes Wolff-Parkinson-White Syndrome?
Doctors aren’t sure what causes Wolff-Parkinson-White (WPW) syndrome. The extra electrical pathway in the heart is present at birth, so it must be caused by some abnormality that occurs during fetal development. A small percentage of patients have been found to have a gene mutation that is thought to be responsible for the WPW syndrome.
In a normal heart, the heartbeat is initiated by the sinus node in the upper right section of the heart muscle. This is where the electrical impulses that start each heartbeat begin. Those impulses then cause travel to the upper chambers of the heart, the atria (upper heart chambers) where contraction occurs. Another node, the atrioventricular node (AV node) then sends the impulse to the ventricles (lower heart chambers) where contractions occur and the blood is pumped out of the heart. The coordination of these events is essential in order to maintain a normal, regular heartbeat and rhythm.
In a heart affected by WPW, however, an extra electrical pathway can interfere with the normal heartbeat. This extra pathway creates a “shortcut” for the electrical impulses. As a result, these impulses may activate activate the heartbeats too early or at the wrong time.
If left untreated, the abnormal heartbeat, arrhythmia or tachycardia, can cause complications, such as low blood pressure, heart failure, and even death.
Who Is at Risk for WPW?
Babies born to parents with WPW syndrome may be more at risk for developing the condition. Babies with other congenital heart defects may also be at a higher risk.
Signs and Symptoms of WPW
The first sign of WPW syndrome is usually a rapid heart rate.
Symptoms of WPW may occur in infancy or in adulthood. In infants, symptoms may include:
- fatigue and lethargy
- loss of appetite
- shortness of breath
- rapid, visible pulsations of the chest
In children, teenagers, and adults, symptoms may include:
- heart palpitations
- a racing heart
- dizziness, lightheadedness, or fainting
- shortness of breath
- sudden death (rarely)
In some people, symptoms will not appear at all or will appear only periodically in short episodes.
How is WPW Diagnosed?
Patients experiencing a fluttering or racing heartbeat usually tell their doctors. In those individuals who don’t experience symptoms, the condition may go unnoticed for years.
If you have a racing heartbeat, your doctor will likely perform a physical exam and conduct tests that measure your heart rate over time to check for tachycardia and diagnose WPW syndrome. These heart tests may include:
This test uses small sensors attached to your chest and arms to record the electrical signals traveling through your heart. Your doctor can check these signals for any signs of an abnormal electrical pathway. You can also do this test at home with a portable device. Your doctor will likely give you either an ECG device called a Holter monitor or an event recorder that can be worn as you perform your daily activities. These monitors can record your heart’s rhythm and rate throughout the day(s).
During this test, the doctor threads a thin, flexible catheter tipped with electrodes through your blood vessels and into various parts of your heart, where they can map its electrical impulses.
How is WPW Treated?
Once you are diagnosed with WPW, you have several treatment options, depending on your symptoms. If you are diagnosed with WPW but don’t have any symptoms, your doctor may recommend that you wait and continue follow-up appointments. If you are experiencing symptoms, however, treatment may include:
The most common method of treatment, this procedure actually destroys the extra electrical pathway in your heart. The doctor inserts a tiny catheter into an artery in your groin and threads it up into your heart. When the tip reaches your heart, the electrodes are heated and this procedure will then destroy the area causing the abnormal heartbeat with radiofrequency energy.
A variety of drugs are available to treat abnormal heart rhythms. These include adenosine, antiarrhythmics, and amiodarone.
Electrical Cardioversion (Shock)
If medications don’t work, doctors may suggest an electrical shock to the heart, which can restore normal rhythm. Doctors administer anesthesia to put you to sleep and then place paddles or patches on your chest to deliver the shock. This procedure is usually reserved for patients whose symptoms are not relieved by other treatments.
Open-heart surgery may also be used to treat WPW syndrome, but usually only if the patient requires the surgery to treat another heart condition.
If you continue to have heart-rhythm problems after treatment, doctors may implant an artificial pacemaker to regulate your heart rhythm.
For those with mild cases of WPW, lifestyle adjustments can help limit abnormal heart rhythms. Avoiding caffeine, tobacco, alcohol, and pseudoephedrine (a nasal decongestant) can help maintain a normal heartbeat. Doctors may also recommend so-called “vagal maneuvers,” which can help slow a fast heart rate. These include coughing, bearing down as if you were having a bowel movement, and placing an ice pack on your face.
What Can Be Expected in the Long-Term?
Patients who use medications to treat WPW may experience unwanted side effects and may not want to continue taking such medications long term. In those cases, other treatments such as catheter ablation may be recommended.
Catheter ablation is successful at curing WPW syndrome in 85 to 95 percent of cases. Success depends on how many alternative electrical pathways you have and where they are in your heart.
Those patients not cured by catheter ablation still have other treatment options, such as cardioversion or open-heart surgery. All patients who have the disorder will require follow-up monitoring to ensure that their hearts are functioning normally.