Electrophysiology: the Wolff-Parkinson-White syndrome

Though tachyarrhythmias occur commonly in patients with the Wolff-Parkinson-White syndrome, many patients remain asymptomatic. Recent studies suggest that routine electrophysiologic testing in these individuals is of limited value. However, electrophysiologic testing remains very helpful in the symptomatic patient for predicting arrhythmia recurrence and for determining accessory pathway location and function. Unfortunately, noninvasive tests to predict high-risk WPW patients has not been proven helpful because of their low specificity. A number of recent studies have shown that autonomic function can markedly improve accessory pathway function and even counteract the effect of antiarrhythmic drugs. Given the frequent failure of antiarrhythmic therapy in the WPW syndrome, there has been increasing interest in nonpharmacologic therapies, including high-energy DC shock and radiofrequency catheter ablation of accessory pathways, which may prove to be more cost-effective than surgery.