Definition Wolff-Parkinson-White (WPW) syndrome is a disturbance in the electrical pathway of the heart that may cause tachycardia, or a rapid heart rate.
What is going on in the body? 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. Heart rates can range from 120 to over 200 beats per minute, compared to a normal heart rate of less than 100 beats per minute.
What are the signs and symptoms of the disease? A person with WPW may notice a rapid heart beat or palpitations, which is 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 be present as well. These include:
What are the causes and risks of the disease? It is not currently known exactly how this condition is inherited, or what causes the extra electrical pathway found in Wolff-Parkinson-White syndrome.
What can be done to prevent the disease? Wolff-Parkinson-White syndrome itself cannot be prevented. However, medications or surgery can be used to prevent symptoms due to arrhythmias.
How is the disease diagnosed? An electrocardiogram (ECG), or graphic recording of the electrical activity of the heart, is used to diagnose this problem. If the abnormal rhythm is present, the individual will have a heart rate of between 120 and 200 beats per minute. If the tachycardia is not occurring while the person is being examined, he or she will appear normal. An ECG is usually abnormal even in the absence of symptoms.
A more specialised 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.
What are the long-term effects of the disease? 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.
What are the risks to others? This disorder is not contagious and does not put other people at risk.
What are the treatments for the disease? 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 and lignocaine.
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. This eliminates the problem of potential fast or irregular heart rates.
What are the side effects of the treatments? 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.
What happens after treatment for the disease? After Wolff-Parkinson-White syndrome is effectively treated, the person can carry out normal activities.
How is the disease monitored? A person with Wolff-Parkinson-White syndrome will need frequent regular ECGs and visits to the doctor. 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 doctor.
Author: Bill Harrison, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
