title: Surface ECG f Wave Analysis of Dofetilide Drug Effect in the Atrium.
abstract: BACKGROUND
  The electrocardiogram (ECG) fibrillatory (f) wave characteristics in atrial fibrillation (AF) could provide important information regarding the efficacy of antiarrhythmic drug therapy.
  
  
  RESULTS
  To measure the effects of dofetilide on the surface ECG f wave characteristics in patients with persistent AF, baseline and post-drug (2 hours after first dose and after multiple doses) ECGs in 31 patients with persistent AF admitted for dofetilide loading were evaluated. A QRST template subtraction algorithm was used to yield an atrial ECG. Fast Fourier transform analysis was performed to evaluate the maximum organizational index (OI), the dominant frequency (DF) in the lead with max OI, the median DF for all leads, and the vector magnitude f wave amplitude. Dofetilide reduced DF in the lead with the max OI (6.32 ± 0.98 Hz at baseline vs. 4.83 ± 0.63 Hz after final dose, P < 0.0001) and median DF (6.46 ± 0.87 Hz vs. 4.92 ± 0.62 Hz, P < 0.0001). Dofetilide also increased the maximum OI from 0.52 ± 0.11 at baseline to 0.59 ± 0.11 after final dose (P = 0.02). Of the 29 patients with long-term follow-up, the 22 (76%) with recurrent AF on dofetilide had a lower baseline DF in the lead with the max OI (6.01 ± 1.08 vs. 6.89 ± 0.46; P = 0.05). The change in DF after dofetilide did not correlate with the change in QTc interval.
  
  
  CONCLUSIONS
  The standard ECG can be used to assess atrial rate in AF. This may be useful to assess antiarrhythmic drug effects for treatment of AF.
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
authors.forename: Viraj P
authors.initials: VP
authors.lastname: Raygor
authors.affiliation: Center for Cardiovascular Innovation and the Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Ng
authors.affiliation: Center for Cardiovascular Innovation and the Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Goldberger
mesh_terms: D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D005583:Fourier Analysis; D006325:Heart Atria / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010627:Phenethylamines / Q000627:therapeutic use*; D012189:Retrospective Studies; D013449:Sulfonamides / Q000627:therapeutic use*
chemical_list: D000889:Anti-Arrhythmia Agents; D010627:Phenethylamines; D013449:Sulfonamides; C063533:dofetilide
keywords: QRST subtraction; atrial fibrillation; cardioversion; dofetilide; dominant frequency; surface ECG