title: Atrial fibrillatory rate and risk of stroke in atrial fibrillation.
abstract: OBJECTIVE
  In atrial fibrillation (AF), a relation between electrocardiogram (ECG) parameters such as fibrillatory wave amplitude and stroke has been sought with conflicting results. In this study, we tested the hypothesis that the atrial fibrillatory rate of surface ECG lead V1 is related to stroke risk and may consequently be helpful for identifying high-risk patients.
  
  
  RESULTS
  Atrial fibrillatory rate of 79 consecutive patients with AF and embolic stroke (age 83 +/- 7 years, 41% male) was compared with those of a matched AF population without stroke (n = 79). Atrial fibrillatory rate was determined from the surface ECG using spatiotemporal QRST cancellation and time-frequency analysis of lead V1. There was no significant difference in any clinical or echocardiographic variable in patients with stroke compared with AF controls without stroke. Atrial fibrillatory rate measured 373 +/- 55 fibrillations per minute (fpm; range 235-505 fpm) in the entire population. There was no fibrillatory rate difference between stroke patients (369 +/- 54 fpm, range 256-505 fpm) and AF controls without stroke (378 +/- 56 fpm, range 235-488 fpm). There was an inverse correlation between fibrillatory rate and age (R = -0.219, P = 0.006). Individuals aged >or=85 years had a significantly lower fibrillatory rate (356 +/- 44 fpm) than individuals aged 65-74 years (384 +/- 56 fpm, P = 0.033) and individuals aged 75-84 years (384 +/- 60 fpm, P = 0.016). In those subgroups, fibrillatory rates were, however, also similar in stroke patients and AF controls.
  
  
  CONCLUSIONS
  Atrial fibrillatory rate obtained from surface ECG lead V1 is not a risk marker for stroke in AF.
authors.affiliation: Department of Cardiology, Lund University, Lund, Sweden. andreas.bollmann@med.lu.se
authors.forename: Andreas
authors.initials: A
authors.lastname: Bollmann
authors.forename: Daniela
authors.initials: D
authors.lastname: Husser
authors.forename: Arne
authors.initials: A
authors.lastname: Lindgren
authors.forename: Martin
authors.initials: M
authors.lastname: Stridh
authors.forename: Bjarne Madsen
authors.initials: BM
authors.lastname: Härdig
authors.forename: Christopher
authors.initials: C
authors.lastname: Piorkowski
authors.forename: Arash
authors.initials: A
authors.lastname: Arya
authors.forename: Leif
authors.initials: L
authors.lastname: Sörnmo
authors.forename: S Bertil
authors.initials: SB
authors.lastname: Olsson
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D020517:Atrial Appendage / Q000503:physiopathology; D001281:Atrial Fibrillation / Q000150:complications / Q000503:physiopathology*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology*; D013923:Thromboembolism / Q000453:epidemiology