title: Change in the Grade of Preexcitation and Progressive Prolongation of S-Delta Interval.
authors.affiliation: Cardiac Electrophysiology Section, Cardiology Department, Hospital Doce de Octubre, Madrid, Spain.
authors.forename: Justo
authors.initials: J
authors.lastname: Juliá
authors.affiliation: Cardiac Electrophysiology Section, Cardiology Department, Hospital Doce de Octubre, Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: López-Gil
authors.affiliation: Cardiac Electrophysiology Section, Cardiology Department, Hospital Doce de Octubre, Madrid, Spain.
authors.forename: Adolfo
authors.initials: A
authors.lastname: Fontenla
authors.affiliation: Cardiac Electrophysiology Section, Cardiology Department, Hospital Doce de Octubre, Madrid, Spain.
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Lozano
authors.affiliation: Cardiac Electrophysiology Section, Cardiology Department, Hospital Doce de Octubre, Madrid, Spain.
authors.forename: Lola
authors.initials: L
authors.lastname: Villagraz
authors.affiliation: Cardiac Electrophysiology Section, Cardiology Department, Hospital Doce de Octubre, Madrid, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Salguero
authors.affiliation: Cardiac Electrophysiology Section, Cardiology Department, Hospital Doce de Octubre, Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Arribas
keywords: WPW syndrome; nodoventricular pathway; preexcitation; preexcited tachycardia