How is wolff-parkinson-white (WPW) diagnosed?
Electrocardiography (ECG) is used to diagnose Wolff-Parkinson-White syndrome, and other cardiac arrhythmias. A trained physician, normally a cardiologist, can recognize patterns of electrical conduction. With this syndrome, the extra pathway will show a pattern different from those of normal conduction. If no irregular patterns show on the ECG, the patient may be sent
home with a 24-hour heart monitor, called a Holter monitor, which will help detect intermittent occurrences. Other studies, such as the cardiac electrophysiologic study (EPS), may be ordered to pinpoint the location of the accessory pathway, and to determine a course of treatment.
In WPW, the extra electrical pathway causes the appearance of a "delta" wave inside the QRS wave. A finding of abnormal delta waves on an EKG alone is insufficient to establish the diagnosis of WPW. The presence of delta waves on an EKG must be accompanied by symptoms due to tachycardia episodes to establish a diagnosis of WPW. Patients found to have delta waves without symptoms related to tachycardias are diagnosed as having only ventricular preexcitation without actually having WPW.
Patients with WPW and some patients with ventricular preexcitation are usually evaluated by a cardiac electrophysiologist (a cardiologist with special training and expertise in electrical disturbances of the heart). Most of these patients undergo an electrophysiology study, which is a study of the electrical system of the heart. Electrophysiology studies are performed either in a cardiac catheterization laboratory or in a special electrophysiology laboratory.
Electrophysiology studies can locate the abnormal electrical pathway, characterize the conduction properties of the abnormal pathway, and assess the risk of life-threatening tachycardias. Also, at the time of electrophysiology study, selected patients with WPW can undergo radiofrequency ablation-a technique that destroys the abnormal electrical pathway using a catheter capable of delivering radiofrequency energy.