Wolff-Parkinson-White Syndrome

Diagnosis

A comprehensive diagnosis at Mayo Clinic helps determine how Wolff-Parkinson-White (WPW) syndrome is affecting the heart, and also the most appropriate treatment for the patient. At Mayo Clinic, an integrated team of electrophysiologists and other heart specialists diagnose WPW.

To diagnose the syndrome, specialists may ask the patient about or test for conditions that may trigger the abnormally fast heartbeat, such as heart disease or a thyroid problem. Several tests may be given to better understand the causes of WPW syndrome.

Electrophysiology (EP) testing and mapping
Mayo Clinic is an international leader in catheter ablation and implantable devices and uses the most advanced technology to treat arrhythmias. The electrophysiology lab has more than 25 years of experience in treating patients who have heart arrhythmias.

In EP testing, catheters (thin, flexible tubes) with electrodes at the tips are threaded through the patient's blood vessels to various spots within the heart. Once in place, the electrodes can precisely map the spread of electrical impulses through the heart.

During the test, the electrophysiologist may use the electrodes to stimulate the heart to beat at rates that may trigger — or halt — an irregular heartbeat. The physician can observe the location of the arrhythmia and the mechanics of the heart that may be causing the irregular heartbeat.

The ability to trigger and then stop WPW syndrome may also be used to test the effectiveness of various treatment methods. For example, if catheter radiofrequency ablation (a minimally-invasive procedure that uses catheters to reach the heart and destroy abnormal heart tissue) is determined by the doctor to be appropriate, the procedure can be performed during EP testing. Read more about catheter radiofrequency ablation.

Stress test
Wolff-Parkinson-White syndrome may be triggered or worsen when the patient exercises. During a stress test, the patient may exercise on a treadmill or stationary bicycle, with an electrocardiogram (ECG) monitoring heart activity. If patients have difficulty exercising, a drug may be given to mimic the effect of exercise on the heart. The stress test can also be used to detect coronary artery disease.

Electrocardiogram (ECG)
Electrodes (sensor patches with wires attached) are placed on the patient's skin to measure the electrical impulses given off by the heart. The ECG measures the timing and duration of each electrical phase in the heartbeat.

Echocardiogram (Doppler echocardiogram)
This test uses sound waves to produce detailed images of the patient's heart. Through a handheld device (transducer) on the patient's chest, sound waves bounce off the heart and are reflected to produce video images of the heart's size, structure and motion. The echocardiogram can help measure the heart's blood volume and the speed and direction of blood flow through the heart.

Some tests involve monitoring the heart during regular activity.

Holter monitor
A Holter monitor is a portable ECG device that the patient wears for a day or more to record the heart's electrical activity during the daily routine.

Event monitor
For irregular heartbeats that occur sporadically, this portable ECG device is kept at home so the patient can attach it and activate the ECG recording only when experiencing symptoms of an arrhythmia. The device is small, about the size of a portable compact disc player, and can be clipped onto clothing. Patients can apply the electrodes (sticky pads with wires) onto their chest. When the patient feels symptoms, a push of a button begins the ECG recording. For certain patients, an implanted recorder may be used.