title: Can orthogonal lead indicators of propensity to atrial fibrillation be accurately assessed from the 12-lead ECG?
abstract: OBJECTIVE
  When analyzing P-wave morphology, the vectorcardiogram (VCG) has been shown useful to identify indicators of propensity to atrial fibrillation (AF). Since VCG is rarely used in the clinical routine, we wanted to investigate if these indicators could be accurately determined in VCG derived from standard 12-lead ECG (dVCG).
  
  
  METHODS
  ECG and VCG recordings from 21 healthy subjects and 20 patients with a history of AF were studied. dVCG was calculated from ECG using the inverse Dower transform. Following signal averaging of P-waves, comparisons were made between VCG and dVCG, where three parameters characterizing signal shape and 15 parameters describing the P-wave morphology were used to assess the compatibility of the two recording techniques. The latter parameters were also used to compare the healthy and the AF groups.
  
  
  RESULTS
  After transformation, P-wave shape was convincingly preserved. P-wave morphology parameters were consistent within the respective groups when comparing VCG and dVCG, with better preservation observed in the healthy group.
  
  
  CONCLUSIONS
  VCG derived from routine 12-lead ECG may be a useful alternate method for studying orthogonal P-wave morphology.
authors.affiliation: Department of Cardiology, Lund University, Sweden. jonas.carlson@med.lu.se
authors.forename: Jonas
authors.initials: J
authors.lastname: Carlson
authors.forename: Rasmus
authors.initials: R
authors.lastname: Havmöller
authors.forename: Alberto
authors.initials: A
authors.lastname: Herreros
authors.forename: Pyotr
authors.initials: P
authors.lastname: Platonov
authors.forename: Rolf
authors.initials: R
authors.lastname: Johansson
authors.forename: Bertil
authors.initials: B
authors.lastname: Olsson
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted; D014672:Vectorcardiography