title: Associations of electrocardiographic P-wave characteristics with left atrial function, and diffuse left ventricular fibrosis defined by cardiac magnetic resonance: The PRIMERI Study.
abstract: BACKGROUND
  Abnormal P-terminal force in lead V1 (PTFV1) is associated with an increased risk of heart failure, stroke, atrial fibrillation, and death.
  
  
  OBJECTIVE
  Our goal was to explore associations of left ventricular (LV) diffuse fibrosis with left atrial (LA) function and electrocardiographic (ECG) measures of LA electrical activity.
  
  
  METHODS
  Patients without atrial fibrillation (n = 91; mean age 59.5 years; 61.5% men; 65.9% white) with structural heart disease (spatial QRS-T angle ≥105° and/or Selvester QRS score ≥5 on ECG) but LV ejection fraction >35% underwent clinical evaluation, cardiac magnetic resonance, and resting ECG. LA function indices were obtained by multimodality tissue tracking using 2- and 4-chamber long-axis images. T1 mapping and late gadolinium enhancement were used to assess diffuse LV fibrosis and presence of scar. P-prime in V1 amplitude (PPaV1) and duration (PPdV1), averaged P-wave-duration, PR interval, and P-wave axis were automatically measured using 12 SLTM algorithm. PTFV1 was calculated as a product of PPaV1 and PPdV1.
  
  
  RESULTS
  In linear regression after adjustment for demographic characteristics, body mass index, maximum LA volume index, presence of scar, and LV mass index, each decile increase in LV interstitial fibrosis was associated with 0.76 mV*ms increase in negative abnormal PTFV1 (95% confidence interval [CI] -1.42 to -0.09; P = .025), 15.3 ms prolongation of PPdV1 (95% CI 6.9 to 23.8; P = .001) and 5.4 ms prolongation of averaged P-duration (95% CI 0.9-10.0; P = .020). LV fibrosis did not affect LA function. PPaV1 and PTFV1 were associated with an increase in LA volumes and decrease in LA emptying fraction and LA reservoir function.
  
  
  CONCLUSIONS
  LV interstitial fibrosis is associated with abnormal PTFV1, prolonged PPdV1, and P-duration, but does not affect LA function.
authors.affiliation: Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland; Division of Cardiology, Department of Medicine, University of New Mexico, Albuquerque, New Mexico.
authors.forename: Theingi
authors.initials: T
authors.lastname: Tiffany Win
authors.affiliation: Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Bharath
authors.initials: B
authors.lastname: Ambale Venkatesh
authors.affiliation: Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Gustavo J
authors.initials: GJ
authors.lastname: Volpe
authors.affiliation: Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Nathan
authors.initials: N
authors.lastname: Mewton
authors.affiliation: Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Patricia
authors.initials: P
authors.lastname: Rizzi
authors.affiliation: Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Ravi K
authors.initials: RK
authors.lastname: Sharma
authors.affiliation: U.S. Food and Drug Administration, Silver Spring, Maryland.
authors.forename: David G
authors.initials: DG
authors.lastname: Strauss
authors.affiliation: Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Joao A
authors.initials: JA
authors.lastname: Lima
authors.affiliation: Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland; The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon. Electronic address: tereshch@ohsu.edu.
authors.forename: Larisa G
authors.initials: LG
authors.lastname: Tereshchenko
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000473:pathology* / Q000503:physiopathology*; D016279:Atrial Function, Left / Q000502:physiology; D015331:Cohort Studies; D004562:Electrocardiography; D004719:Endomyocardial Fibrosis / Q000175:diagnosis* / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
keywords: Atrial fibrillation; Fibrosis; Left atrium function; Left ventricle; P-terminal force in V(1)