What is an Accessory Pathway?

An accessory pathway is a conductive pathway in the heart that allows electrical signals to pass directly from the atria to the ventricles, instead of being routed through the atrioventricular (AV) node like they are in healthy individuals. The percentage of people born with an accessory pathway is somewhat unclear, as sometimes it causes no problems, while in other instances it may lead to the development of cardiac arrhythmias. One condition that can sometimes be observed in patients with an accessory pathway is Wolff-Parkinson-White syndrome.

The accessory pathway can conduct signals very rapidly and recovers very quickly. It can result in the premature delivery of electrical signals to the ventricles, causing cardiac arrhythmias where the heart beats abnormally because the cycle of electrical signals is disrupted. Additionally, arrhythmias that start in the atria can spread to the ventricles through the accessory pathway when normally they would be limited by the AV node.

A medical study like an electrocardiogram can be used to identify an arrhythmia. Cardiac arrhythmias have certain signatures that care providers can use to identify their origins. In the case of a patient with an accessory pathway, if abnormal electrical signaling is detected, the doctor can determine the severity of the abnormality and discuss the risks with the patient. A primary concern is that a patient could have a heart attack as a result of an arrhythmia.

Treatment for an accessory pathway involves surgical ablation to damage the tissue so that it cannot carry electrical signals anymore. A commonly used technique involves the use of radio waves to bombard the extra tissue in the heart. There are risks associated with ablation procedures and patients should discuss these risks with care before consenting to surgery. It is also possible to use medications to control the heart's electrical rhythms in some cases.

If an accessory pathway is diagnosed, patients may want to ask how severe it is, what any potential complications may be, and if treatments are recommended. If a treatment is proposed, patients can ask how it works, what it is used for, what the alternatives are, and if there are any risks associated with treatment. It is important to get as much information possible when making medical decisions to make an informed choice possible. Patients may also want information they can use when discussing their options with friends and family as well as caregivers who may play a role in treatment and recovery.