title: [The electrophysiology of Wolff-Parkinson-White in the asymptomatic patient with activity or with high professional risk].
abstract: OBJECTIVE
  Describe the electrophysiological characteristics in subjects with asymptomatic Wolff-Parkinson-White with sports activities or high professional responsibility.
  
  
  METHODS
  Nineteen subjects, mean age 33 ± 13 years (group A). The electrophysiological characteristics were compared with a matched group with symptomatic WPW (group B).
  
  
  RESULTS
  At baseline the anterograde refractory period and the anterograde conduction 1:1 over the accessory pathway were longer in group A (300 ± 48 ms vs 262 ± 32 ms, p < 0.05 and 355 ± 108 ms vs 307 ± 86 ms, p < 0.05), respectively. None of group A had a anterograde refractory period< 250 ms and 58% showed absence of retrograde conduction over the accessory pathway vs 4% of group B (p < 0.001). Induction of tachycardia was significantly less in group A (5%) than in group B (92%) (p < 0.001). Atrial fibrillation was induced in only one of group A vs 32% of group B (p < 0.001).
  
  
  CONCLUSIONS
  We confirm the benign electrophysiological characteristics in asymptomatic compared to symptomatic subjects. Poor anterograde conduction along with absence of retrograde conduction explains the low frequency of tachyarrhythmias and would not support the routine investigation of all asymptomatic subjects. But, due to possible consequences, remains the systematic indication for preventive ablation in the subgroup of asymptomatic subjects with sporting activities or high professional responsibility.
authors.affiliation: Curso de Posgrado de Alta Especialidad en Electrofisiología Cardiaca, México D.F., México. enve@prodigy.net.mx
authors.forename: Enrique
authors.initials: E
authors.lastname: Velázquez-Rodríguez
authors.forename: Alex
authors.initials: A
authors.lastname: Pacheco-Bouthillier
authors.forename: Horacio
authors.initials: H
authors.lastname: Rodríguez-Piña
authors.forename: Luz María
authors.initials: LM
authors.lastname: Deras-Mejía
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D058070:Asymptomatic Diseases; D055724:Electrophysiological Phenomena; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016272:Occupational Health; D012307:Risk Factors; D013177:Sports; D014927:Wolff-Parkinson-White Syndrome / Q000503:physiopathology*; D055815:Young Adult