title: 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.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Cardiology, Electrophysiology, and Cardiac Pacing Unit, San Raffaele University Hospital, Milan, Italy. carlo.pappone@hsr.it
authors.forename: Carlo
authors.initials: C
authors.lastname: Pappone
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Santinelli
authors.forename: Salvatore
authors.initials: S
authors.lastname: Rosanio
authors.forename: Gabriele
authors.initials: G
authors.lastname: Vicedomini
authors.forename: Stefano
authors.initials: S
authors.lastname: Nardi
authors.forename: Alessia
authors.initials: A
authors.lastname: Pappone
authors.forename: Valter
authors.initials: V
authors.lastname: Tortoriello
authors.forename: Francesco
authors.initials: F
authors.lastname: Manguso
authors.forename: Patrizio
authors.initials: P
authors.lastname: Mazzone
authors.forename: Simone
authors.initials: S
authors.lastname: Gulletta
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Oreto
authors.forename: Ottavio
authors.initials: O
authors.lastname: Alfieri
mesh_terms: D000293:Adolescent; D000328:Adult; D001281:Atrial Fibrillation / Q000209:etiology; D002648:Child; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D014927:Wolff-Parkinson-White Syndrome / Q000150:complications / Q000175:diagnosis*