title: Evaluation of the P Wave Axis in Patients With Systemic Lupus Erythematosus.
abstract: BACKGROUND
  P wave axis is one of the most practical clinical tool for evaluation of cardiovascular disease. The aim of our study was to evaluate the P wave axis in electrocardiogram (ECG), left atrial function and association between the disease activity score in patients with systemic lupus erythematosus (SLE).
  
  
  METHODS
  Standard 12-lead surface ECGs were recorded by at a paper speed of 25 m/s and an amplifier gain of 10 mm/mV. The heart rate (HR), the duration of PR, QRS, QTd (dispersion), the axis of P wave were measured by ECG machine automatically.
  
  
  RESULTS
  The P wave axis was significantly increased in patients with SLE (49 ± 20 vs. 40 ± 18, P = 0.037) and the disease activity score was found positively correlated with P wave axis (r: 0.382, P = 0.011). The LA volume and the peak systolic strain of the left atrium (LA) were statistically different between the groups (P = 0.024 and P = 0.000). The parameters of the diastolic function; E/A and E/e' were better in the control group than the patients with SLE (1.1 ± 0.3 vs. 1.3 ± 0.3, P = 0.041 and 6.6 ± 2.8 vs. 5.4 ± 1.4, P = 0.036, respectively).
  
  
  CONCLUSIONS
  P wave axis was found significantly increased in patients with SLE and positively correlated with SELENA-SLEDAI score. As the risk score increases in patients with SLE, P wave axis changes which may predict the risk of all-cause and cardiovascular mortality.
authors.affiliation: Kartal Kosuyolu Education and Research Hospital, Department of Cardiology, Istanbul, Turkey.
authors.forename: Rezzan Deniz
authors.initials: RD
authors.lastname: Acar
authors.affiliation: Kartal Kosuyolu Education and Research Hospital, Department of Cardiology, Istanbul, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Bulut
authors.affiliation: Department of Internal Medicine, Bilim University, Istanbul, Turkey.
authors.forename: Şencan
authors.initials: Ş
authors.lastname: Acar
authors.affiliation: Kartal Kosuyolu Education and Research Hospital, Department of Cardiology, Istanbul, Turkey.
authors.forename: Servet
authors.initials: S
authors.lastname: Izci
authors.affiliation: Kartal Kosuyolu Education and Research Hospital, Department of Cardiology, Istanbul, Turkey.
authors.forename: Serdar
authors.initials: S
authors.lastname: Fidan
authors.affiliation: Kartal Kosuyolu Education and Research Hospital, Department of Cardiology, Istanbul, Turkey.
authors.forename: Mahmut
authors.initials: M
authors.lastname: Yesin
authors.affiliation: Kartal Kosuyolu Education and Research Hospital, Department of Cardiology, Istanbul, Turkey.
authors.forename: Suleyman Cagan
authors.initials: SC
authors.lastname: Efe
keywords: Left Atrial Strain; Left Atrial Volume; P Wave Axis; Systemic Lupus Erythematosus