Wolff-Parkinson-White Syndrome

The heart muscle is responsible for circulating blood throughout the body. The heart is aided by a group of specialized cells known as the sinoatrial node (also called the sinus node) which is located in the upper right chamber of the heart. The sinus node is the heart's natural pacemaker and controls the rhythm of the heart.

In a normal heart, an electrical impulse from the sinus node signals the upper chambers of the heart (the atria) to contract, pumping blood into the lower chambers (the ventricles). When the ventricles are full of blood, electrical signals from the sinus node travel along a pathway of cells to the ventricles, causing them to contract.

When a person is born with an extra electrical connection between the atria and the ventricles, the disorder is called Wolff-Parkinson-White syndrome. This extra electrical pathway makes it more likely that a person will develop rapid or irregular heartbeats, or arrhythmias. Usually these arrhythmias develop during the teenage years or early 20s. They can begin as early as the first year of life or after the age of 60.

Symptoms

An infant with symptoms of Wolff-Parkinson-White syndrome can develop heart failure. Symptoms include:

  • Lethargy
  • Loss of appetite
  • Rapid, visible pulsations of the chest
  • Shortness of breath

In teenagers or young adults, symptoms of Wolff-Parkson-White syndrome may include:

In young, physically active people, these episodes usually cause few symptoms.

Later in life, if a patient has paroxysmal supraventricular tachycardia due to Wolff-Parkinson-White syndrome, they will experience more symptoms such as fainting, shortness of breath and chest pain.

Atrial fibrillation may be a particular danger if a patient has Wolff-Parkinson-White syndrome. The extra electrical pathway can send impulses to the ventricles much faster than the normal pathway through the atrioventricular node. As a result, the ventricles contract at an extremely fast rate. This condition makes the heart very inefficient at pumping blood because the chambers are unable to fill with blood before contracting, which can be life threatening. Such a rapid heart rate can also build into ventricular fibrillation, which is fatal unless treated immediately. On rare occasions, Wolff-Parkinson-White syndrome can lead to a rapid, life-threatening heart rate during atrial fibrillation.


Causes and Risk Factors

Wolff-Parkinson White syndrome is present from birth and its cause is often unknown. In a small number of patients the condition is caused by a gene mutation. Wolff-Parkinson White syndrome is also associated with certain forms of congenital heart disease, such as Ebstein's anomaly.

Diagnosis

Diagnosis of Wolff-Parkinson White syndrome will generally begin with the physician taking a medical history and performing a physical exam. If the patient is experiencing an episode of tachycardia, a rapid pulse above 100 beats per minute in adults or 150 beats per minute in infants may be observed. If the patient is not experiencing a tachycardia event at the time of the physical exam, the physician may order a Holter monitor test to record the heart's electrical activity over a 24-hour period as the person goes about regular activities outside the hospital.

Other diagnostic tests may include an electrocardiogram (EKG), a painless procedure that provides a picture of the electrical activity of the heart. Electrophysiology studies may also be done to look at the electrical system of the heart.

Treatments

During an episode of rapid heart rate due to Wolff-Parkinson-White syndrome, physicians can do one of several things that will stimulate the vagus nerve to slow the heart rate. This stimulation is most effective when applied soon after the arrhythmia starts and is usually performed by or under a doctor's supervision. However, people who frequently have this problem can learn to do it themselves. These methods include:

  • Plunging the face into a bowl of ice-cold water
  • Rubbing the neck just below the angle of the jaw to stimulate an area on the carotid artery
  • Straining as if having a difficult bowel movement

If this approach does not work, antiarrhythmic medication such as verapamil or adenosine can be given intravenously to stop the arrhythmia. These drugs must then be taken indefinitely to prevent future episodes of rapid heart rate.

In infants and children under 10 years old, digoxin may be given to control episodes of rapid heart rate due to Wolff-Parkinson-White syndrome. Usually this drug is stopped before a person with this syndrome reaches puberty. Adults with Wolff-Parkinson-White syndrome are at greater risk of developing atrial fibrillation that degenerates into ventricular fibrillation.

The extra electrical pathway can be destroyed using catheter ablation. This has a high rate of success and is particularly helpful in cases where a young patient might otherwise need to take antiarrhythmic drugs for the rest of their life.

The knowledgeable and highly trained staff at the Cedars-Sinai Heart Institute will work with each patient to determine the best treatment option.

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