Wolff-parkinson-white Syndrome

This heart rhythm disturbance is caused by an extra pathway through which electrical impulses travel in the heart. This extra bundle of tissue, also known as the bundle of Kent, is present from the time of birth.

The extra pathway may cause electrical impulses in the heart to arrive at the ventricles too soon. This creates an irregular type of heartbeat, or arrhythmia, that may cause symptoms.

A person with WPW can have episodes when the rate ranges from 120 to over 200 beats per minute, compared to the normal 60 to 100 beats per minute.

A person with WPW may notice a rapid heart beat or palpitations (a term for an unusual awareness of one's own heartbeat). Blood pressure may fall if the heart rate becomes extremely fast.

Depending on the person's underlying medical condition, other symptoms may include:

• chest pain
• shortness of breath
• dizziness, or lightheadedness
• passing out (syncope)

Sometimes this condition is discovered incidentally on a routine electrocardiogram. If the person's heart rate remains normal despite evidence of the abnormal conduction pathway, and the person has no symptoms, the condition can be monitored for the time being without treatment.

It is not currently known exactly how this condition is inherited, or what causes the extra electrical pathway found in Wolff-Parkinson-White syndrome.

Wolff-Parkinson-White syndrome itself cannot be prevented. However, medications or surgery can be used to prevent symptoms due to arrhythmias.

An electrocardiogram (ECG), a graphic recording of the electrical activity of the heart, is used to diagnose this problem.

If the abnormal conduction is present, the individual may have a heart rate of between 120 and 200 beats per minute. If the tachycadia is not occurring while the person is being examined, he or she will appear normal. The ECG is usually abnormal even in the absence of symptoms.

A more specialized test, known as an electrophysiology study, can also be performed. This test involves placing a catheter, or thin tube, through the skin and into an artery in the groin. The catheter is then advanced into the heart to map its electrical activity. This technique can be used to both diagnose and treat the disorder.

In rare circumstances, the arrhythmia caused by Wolff-Parkinson-White syndrome can be fatal. However, episodes do not last for very long in most people.

This disorder is not contagious and does not put other people at risk.

Medications can be used to stop an arrhythmia by interrupting or slowing the abnormal electrical activity in the heart. These medications, called anti-arrhythmics, include procainamide (i.e., Procanbid, Pronestyl), or amiodarone (i.e., Cardone, Pacerone).

Another approach is to map the heart's electrical activity by means of an electrophysiologic study. A radio frequency can be delivered through the catheter to destroy the abnormal pathway. Once the pathway is destroyed, no electrical activity can be conducted in the area of the heart tissue that is triggering the arrhythmia. This eliminates the problem of potential fast or irregular heart rates.

In some persons with WPW, the abnormal heart tissue may lie too close to the cells of the normal conduction pathway to risk the radiofrequency procedure. In this event, a permanent pacemaker can be used to control the heart rate.

Anti-arrhythmics may cause heart rate or blood pressure abnormalities as well as allergic reactions. A person may also develop other arrhythmias as a result of certain heart medications.

After Wolff-Parkinson-White syndrome is effectively treated, the person can carry out normal activities.

A person with Wolff-Parkinson-White syndrome will need frequent regular ECGs and visits to the healthcare provider. Repeat electrophysiologic studies are generally not necessary, unless the problem comes back after the initial treatment. Any new or worsening symptoms should be reported to the healthcare provider.