title: P-wave characteristics and histological atrial abnormality.
abstract: BACKGROUND
  Fibro-fatty transformation is believed to be the leading cause of deteriorated atrial conduction; however, any direct assessment in relation to P-wave characteristics is lacking. We sought to assess P-wave morphology (PWM) and duration (PWD) in relation to histology of the atrial myocardium.
  
  
  OBJECTIVE
  Atrial specimens were collected from 11 patients who died from cardiovascular causes (7 men; median age 73 years).
  
  
  METHODS
  Tissue samples were taken at the level of superior and inferior PVs, center of posterior left atrial wall, terminal crest (CT) and Bachmann's bundle (BB) for assessment of fibro-fatty tissue extent. Standard 12-lead ECGs in sinus rhythm recorded during hospital stay were used for manual assessment of P-wave. Partial interatrial block (pIAB) was defined as a prolonged (≥ 120 ms) and bimodal P-wave in any lead on 12-lead ECG.
  
  
  RESULTS
  The median PWD was 160 (120-200) ms. Fibrosis extent in CT highly correlated to PWD (r=0.914, p<0.001). The combination of fibrosis extent and fatty tissue in BB (16%, range 1%-41%), CT (18%, range 3%-47%) or superior PV (15%, range 6%-24%) correlated to PWD (r=0.627, p=0.039; r=0.795, p=0.003; and r=0.668, p=0.025, respectively). pIAB pattern was observed in 10 subjects; however, it was not associated with either fibrosis or fatty tissue content at any sampling location.
  
  
  CONCLUSIONS
  Our findings further support causal association between PWD and the extent of structural abnormalities in the atrial myocardium and the major atrial conduction routes.
authors.affiliation: Department of Cardiology, Lund University Hospital, Lund University, Lund, Sweden; Department of Electrophysiology, Heart Center Dresden, Dresden University of Technology, Dresden, Germany. Electronic address: dr.huoyan@googlemail.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Huo
authors.affiliation: Almazov Federal Center for Heart, Blood and Endocrinology, St. Petersburg, Russia.
authors.forename: Lubov
authors.initials: L
authors.lastname: Mitrofanova
authors.affiliation: Almazov Federal Center for Heart, Blood and Endocrinology, St. Petersburg, Russia.
authors.forename: Victoria
authors.initials: V
authors.lastname: Orshanskaya
authors.affiliation: Department of Cardiology, Lund University Hospital, Lund University, Lund, Sweden.
authors.forename: Petter
authors.initials: P
authors.lastname: Holmberg
authors.affiliation: Department of Cardiology, Lund University Hospital, Lund University, Lund, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Holmqvist
authors.affiliation: Department of Cardiology, Lund University Hospital, Lund University, Lund, Sweden.
authors.forename: Pyotr G
authors.initials: PG
authors.lastname: Platonov
mesh_terms: D000200:Action Potentials; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000473:pathology* / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D005355:Fibrosis / Q000473:pathology / Q000503:physiopathology; D006325:Heart Atria / Q000473:pathology* / Q000503:physiopathology*; D006329:Heart Conduction System / Q000473:pathology* / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D032383:Myocytes, Cardiac / Q000473:pathology*
keywords: Fibro-fatty transformation; P-wave duration; P-wave morphology