title: QT interval measurement and correction in patients with atrial flutter: a pilot study.
abstract: OBJECTIVE
  Measurement of QT intervals during atrial flutter (AFL) is relevant to monitor the safety of drug delivery. Our aim is to compare QT and QTc intervals in AFL patients before and after catheter ablation in order to validate QT measurement during AFL.
  
  
  METHODS
  25 patients suffering from AFL underwent catheter ablation; 9 were in sinus rhythm and 16 were in AFL at the time of the procedure. Holter ECGs were continuously recorded before, during and after the procedure. In AFL signals, flutter waves were subtracted using a previously-validated deconvolution-based method. Fridericia's QTc was computed before and after ablation after hysteresis reduction.
  
  
  RESULTS
  Comparing QTc values obtained before and after ablation showed that (1) the intervention did not significantly affect QTc, and (2) the QTc during AFL was concordant with the QTc value in sinus rhythm.
  
  
  CONCLUSIONS
  QTc can be reliably measured in patients with AFL using flutter wave subtraction and hysteresis reduction.
authors.affiliation: Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, Canada; Département de Physiologie, Institut de Génie Biomédical, Université de Montréal, Canada. Electronic address: vincent.jacquemet@umontreal.ca.
authors.forename: V
authors.initials: V
authors.lastname: Jacquemet
authors.affiliation: Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Cassani González
authors.affiliation: Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Sturmer
authors.affiliation: Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Dubé
authors.affiliation: Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Sharestan
authors.affiliation: Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, Canada; Département de Physiologie, Institut de Génie Biomédical, Université de Montréal, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Vinet
authors.affiliation: Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, Canada.
authors.forename: O
authors.initials: O
authors.lastname: Mahiddine
authors.affiliation: Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, Canada; Département de Physiologie, Institut de Génie Biomédical, Université de Montréal, Canada.
authors.forename: A R
authors.initials: AR
authors.lastname: Leblanc
authors.affiliation: Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Becker
authors.affiliation: Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, Canada; Département de Pharmacologie, Université de Montréal, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Kus
authors.affiliation: Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Nadeau
mesh_terms: D000368:Aged; D001282:Atrial Flutter / Q000503:physiopathology* / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D013382:Subtraction Technique
keywords: Atrial flutter; Catheter ablation; QT intervals