title: The impact of hemodialysis on the dispersion of ventricular repolarization.
abstract: BACKGROUND
  Sudden cardiac death is prevalent in chronic hemodialysis (HD) patients while the dialysis process may have arrhythmogenic potential. We sought to examine the effect of HD on conventional electrocardiographic parameters as well as on novel indexes of repolarization, given that increased spatial dispersion of repolarization is related to ventricular arrhythmias.
  
  
  METHODS
  We recorded clinical, echocardiographic, and laboratory parameters as well as electrocardiographic indexes before and after a single HD session. Specifically, we calculated the QTc interval, the QRS duration, the T peak-to-end (Tpe) interval, and the Tpe/QT ratio.
  
  
  RESULTS
  The study population consisted of 66 chronic HD patients (mean age: 68.9 ± 11.8 years, 40 males). Heart rate, blood pressure, QRS duration, QTc interval, and QT dispersion did not change significantly after the HD session. However, the Tpe interval and the Tpe/QT ratio increased significantly (80 [65-90] ms vs 85 [77.5-100] ms; P = 0.04, and 0.21 [0.18-0.24] vs 0.25 [0.21-0.28]; P = 0.05, respectively). Correlation analysis and multiple regression analysis failed to show significant associations between the baseline parameters and the baseline values of Tpe and Tpe/QT or between the change of the laboratory parameters during HD and the corresponding change of the Tpe and the Tpe/QT values. No significant arrhythmias were observed during the HD sessions.
  
  
  CONCLUSIONS
  HD induces an increase in novel markers of spatial dispersion of ventricular repolarization. Whether the assessment of these indexes of heterogeneity of repolarization at baseline or their change during HD has a prognostic value with regard to future untoward events, remains to be elucidated.
authors.affiliation: Department of Cardiology, University of Ioannina Medical School, Ioannina, Greece.
authors.forename: Kallirroi
authors.initials: K
authors.lastname: Kalantzi
authors.forename: Chara
authors.initials: C
authors.lastname: Gouva
authors.forename: Konstantinos P
authors.initials: KP
authors.lastname: Letsas
authors.forename: Aphrodite
authors.initials: A
authors.lastname: Vlachopanou
authors.forename: Valerios
authors.initials: V
authors.lastname: Foulidis
authors.forename: Aris
authors.initials: A
authors.lastname: Bechlioulis
authors.forename: Konstantinos P
authors.initials: KP
authors.lastname: Katopodis
authors.forename: John A
authors.initials: JA
authors.lastname: Goudevenos
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Korantzopoulos
mesh_terms: D000368:Aged; D004562:Electrocardiography; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications / Q000503:physiopathology*; D008297:Male; D010865:Pilot Projects; D006435:Renal Dialysis