Wolff-Parkinson-White syndrome is a condition in which your heart has an extra electrical conduction pathway – called an accessory pathway. This can cause an abnormal heart rhythm (arrhythmia) and rapid heart rate (tachycardia).

The accessory pathway is made up of muscle fibres which connect the atria and ventricles of the heart. It is caused by incomplete separation of muscular bundles which connected the atria and ventricles during normal foetal development.

Because the pathway exists outside the normal heart conduction system, it causes abnormally early transmission of impulses from your atria into the ventricles. This can bring about arrhythmias that cause your heart to beat at a very fast rate.

When the arrhythmia occurs you may experience symptoms such as palpitations, dizziness or fainting. A number of people may have no symptoms or have only mild, short-lived symptoms.

The accessory pathway can be seen on an electrocardiogram (ECG). Your cardiologist will be able to diagnose Wolff-Parkinson-White syndrome and inform you of the most appropriate form of treatment for this condition.

Treatment may involve drug therapy or electrophysiology studies, with a view to cure with radiofrequency catheter ablation.

This information was first published in You and Your Heart - an education booklet for patients, families and friends. © 2006 Northern Sydney Central Coast Area Health Service