Cardiac Electrophysiology Usefulness of Invasive Electrophysiologic Testing to Stratify the Risk of Arrhythmic Events in Asymptomatic Patients With Wolff-Parkinson-White Pattern Results From a Large Prospective Long-Term Follow-Up Study

OBJECTIVES The aim of this study was to assess in a large cohort of asymptomatic subjects with Wolff-Parkinson-White (WPW) pattern the usefulness of invasive electrophysiologic testing (EPT) in predicting the occurrence of arrhythmic events over a five-year follow-up. BACKGROUND Sudden death may be the first clinical manifestation of the WPW syndrome in previously asymptomatic patients. Serial EPTs have been proposed to identify patients at risk. METHODS A total of 212 consecutive asymptomatic WPW patients were enrolled after a baseline EPT; patients were followed for five years, and 162 patients (115 noninducible and 47 inducible) patients underwent a second EPT. RESULTS After a mean follow-up of 37.7 months, 33 patients became symptomatic. Of the 115 noninducible patients, 18.2% lost anterograde accessory pathway (AP) conduction, 30% retrograde AP conduction, and only 4 (3.4%) developed symptomatic supraventricular tachycardia (SVT). Of the 47 inducible patients, 25 with sustained atrioventricular reciprocating tachycardia (AVRT) and atrial fibrillation (AF), and 4 with nonsustained AVRT and AF became symptomatic for SVT (n 21) and AF (n 8). They were younger, had shorter AP anterograde refractory periods, and multiple APs compared to patients who remained asymptomatic (for all comparisons, p 0.0001). Of the eight patients with symptomatic episodes of AF and inducible sustained AF, two had a resuscitated cardiac arrest and one died suddenly; all three patients were inducible for AVRT and AF and had multiple APs. CONCLUSIONS In asymptomatic WPW subjects, EPT may be a valuable tool to stratify the risk of symptomatic and fatal arrhythmic events. (J Am Coll Cardiol 2003;41:239–44) © 2003 by the American College of Cardiology Foundation