title: Physiological variation in left atrial transverse orientation does not influence orthogonal P-wave morphology.
abstract: BACKGROUND
  It has previously been demonstrated that orthogonal P-wave morphology in healthy athletes does not depend on atrial size, but the possible impact of left atrial orientation on P-wave morphology remains unknown. In this study, we investigated if left atrial transverse orientation affects P-wave morphology in different populations.
  
  
  METHODS
  Forty-seven patients with atrial fibrillation, 21 patients with arrhythmogenic right ventricular cardiomyopathy, 67 healthy athletes, and 56 healthy volunteers were included. All underwent cardiac magnetic resonance imaging or computed tomography and the orientation of the left atrium was determined. All had 12-lead electrocardiographic recordings, which were transformed into orthogonal leads and orthogonal P-wave morphology was obtained.
  
  
  RESULTS
  The median left atrial transverse orientation was 87 (83, 91) degrees (lower and upper quartiles) in the total study population. There was no difference in left atrial transverse orientation between individuals with different orthogonal P-wave morphologies.
  
  
  CONCLUSIONS
  The physiological variation in left atrial orientation was small within as well as between the different populations. There was no difference in left atrial transverse orientation between subjects with type 1 and type 2 P-wave morphology, implying that in this setting the P-wave morphology was more dependent on atrial conduction than orientation.
authors.affiliation: Department of Cardiology, Lund University and Center for Integrative Electrocardiology at Lund University, Lund, Sweden.
authors.forename: Richard
authors.initials: R
authors.lastname: Petersson
authors.affiliation: Department of Clinical Physiology, Skåne University Hospital, Lund University, Lund, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Mosén
authors.affiliation: Department of Clinical Physiology, Skåne University Hospital, Lund University, Lund, Sweden.|Physiotherapy, Department of Health Sciences, Lund University, Lund, Sweden.
authors.forename: Katarina
authors.initials: K
authors.lastname: Steding-Ehrenborg
authors.affiliation: Department of Cardiology, Lund University and Center for Integrative Electrocardiology at Lund University, Lund, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Carlson
authors.affiliation: Department of Cardiology, Lund University and Center for Integrative Electrocardiology at Lund University, Lund, Sweden.
authors.forename: Lisa
authors.initials: L
authors.lastname: Faxén
authors.affiliation: Department of Cardiology, Lund University and Center for Integrative Electrocardiology at Lund University, Lund, Sweden.
authors.forename: Alan
authors.initials: A
authors.lastname: Mohtadi
authors.affiliation: Department of Cardiology, Lund University and Center for Integrative Electrocardiology at Lund University, Lund, Sweden.
authors.forename: Pyotr G
authors.initials: PG
authors.lastname: Platonov
authors.affiliation: Department of Cardiology, Lund University and Center for Integrative Electrocardiology at Lund University, Lund, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Holmqvist
mesh_terms: D000328:Adult; D056352:Athletes; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D016275:Atrial Function / Q000502:physiology*; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging; D006329:Heart Conduction System / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
keywords: P-wave morphology; atrial electrophysiology; atrial orientation; atrium; echocardiography; electrocardiography