title: Time-domain and morphological analysis of the P-wave. Part I: Technical aspects for automatic quantification of P-wave features.
abstract: BACKGROUND
  Time-domain and morphological analysis of P-wave from surface electrocardiogram has been extensively used to identify patients prone to atrial arrhythmias, especially atrial fibrillation (AF). However, since no standard procedure exists for P-wave preprocessing, standardization of cut-off values for P-wave duration and morphological features is difficult. This study is a methodological investigation of P-wave preprocessing procedures for automatic time-domain and morphological analysis.
  
  
  METHODS
  We compared, on simulated and real data, the P-wave template obtained applying three alignment algorithms with that obtained without alignment, in terms of template error, shift error, P-wave duration, and morphological parameters. We also proposed automatic algorithms for estimation of P-wave duration.
  
  
  RESULTS
  We found that alignment is necessary for a reliable extraction of P-wave template by the averaging procedure, in order to perform time-domain and morphological analysis. On simulated and real data, the error on P-wave duration can be as high as 30 ms on a template obtained without alignment; if alignment procedure is performed, the error on P-wave duration is negligible. Analogously, morphological features are correctly estimated only on a P-wave template obtained with P-waves alignment. We also found that the proposed algorithm for the automatic estimation of the P-wave duration gave reliable results.
authors.affiliation: Department of Technologies and Health, Istituto Superiore di Sanità, Rome, Italy. federica.censi@iss.it
authors.forename: Federica
authors.initials: F
authors.lastname: Censi
authors.forename: Chiara
authors.initials: C
authors.lastname: Ricci
authors.forename: Giovanni
authors.initials: G
authors.lastname: Calcagnini
authors.forename: Michele
authors.initials: M
authors.lastname: Triventi
authors.forename: Renato P
authors.initials: RP
authors.lastname: Ricci
authors.forename: Massimo
authors.initials: M
authors.lastname: Santini
authors.forename: Pietro
authors.initials: P
authors.lastname: Bartolini
mesh_terms: D000465:Algorithms; D001185:Artificial Intelligence; D001281:Atrial Fibrillation / Q000175:diagnosis*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D006801:Humans; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity