title: Automatic p wave analysis over 24 hours in patients with paroxysmal or persistent atrial fibrillation.
abstract: BACKGROUND
  Patients with atrial fibrillation (AF) often exhibit abnormalities of P wave morphology during sinus rhythm. We examined a novel method for automatic P wave analysis in the 24-hour-Holter-ECG of 60 patients with paroxysmal or persistent AF and 12 healthy subjects.
  
  
  METHODS
  Recorded ECG signals were transferred to the analysis program where 5-10 P and R waves were manually marked. A wavelet transform performed a time-frequency decomposition to train neural networks. Afterwards, the detected P waves were described using a Gauss function optimized to fit the individual morphology and providing amplitude and duration at half P wave height.
  
  
  RESULTS
  >96% of P waves were detected, 47.4 +/- 20.7% successfully analyzed afterwards. In the patient population, the mean amplitude was 0.073 +/- 0.028 mV (mean variance 0.020 +/- 0.008 mV(2)), the mean duration at half height 23.5 +/- 2.7 ms (mean variance 4.2 +/- 1.6 ms(2)). In the control group, the mean amplitude (0.105 +/- 0.020 ms) was significantly higher (P < 0.0005), the mean variance of duration at half height (2.9 +/- 0.6 ms(2)) significantly lower (P < 0.0085).
  
  
  CONCLUSIONS
  This method shows promise for identification of triggering factors of AF.
authors.affiliation: Department of Medicine--Cardiology, University of Bonn, Bonn, Germany. alexander.bitzen@ukb.uni-bonn.de
authors.forename: Alexander
authors.initials: A
authors.lastname: Bitzen
authors.forename: Karsten
authors.initials: K
authors.lastname: Sternickel
authors.forename: Thorsten
authors.initials: T
authors.lastname: Lewalter
authors.forename: Jörg Otto
authors.initials: JO
authors.lastname: Schwab
authors.forename: Alexander
authors.initials: A
authors.lastname: Yang
authors.forename: Jan Wilko
authors.initials: JW
authors.lastname: Schrickel
authors.forename: Markus
authors.initials: M
authors.lastname: Linhart
authors.forename: Christian
authors.initials: C
authors.lastname: Wolpert
authors.forename: Werner
authors.initials: W
authors.lastname: Jung
authors.forename: Peter
authors.initials: P
authors.lastname: David
authors.forename: Berndt
authors.initials: B
authors.lastname: Lüderitz
authors.forename: Georg
authors.initials: G
authors.lastname: Nickenig
authors.forename: Lars
authors.initials: L
authors.lastname: Lickfett
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology*; D016022:Case-Control Studies; D015716:Electrocardiography, Ambulatory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted; D018709:Statistics, Nonparametric; D013997:Time Factors