title: Study of ventricular electrical systole in patients with end-stage kidney disease on hemodialysis.
abstract: BACKGROUND
  Patients with end-stage kidney disease (ESKD) experience elevated cardiac stress because of the repetitive and intermittent character of dialysis. Changes in ventricular electrical systole induced by necessary dialysis significantly contribute to predict sudden death due to arrhythmia in ESKD.
  
  
  OBJECTIVE
  The major objective of this study was to assess the behavior of ventricular repolarization in dialysis by analyzing QTc interval and QTc dispersion.
  
  
  METHODS
  This study sample consisted of 47 patients undergoing hemodialysis (61.7% males and 38.3% females), whose mean age was 66.79±13.16 years. All of them underwent three electrocardiograms performed before, during and after one dialysis session. Ventricular electrical systole was analyzed later.
  
  
  RESULTS
  An increase in maximum QTc interval and QTc dispersion associated with dialysis was observed. In addition, an increase in the number of individuals meeting the electrocardiographic criteria for left ventricular hypertrophy (LVH) was observed. After dialysis, higher means of the maximum QTc interval (473 ± 27.63 mseg) and of the QTc dispersion (58.95 ± 18.87 mseg) were observed in individuals with LVH as compared with those in individuals without LVH (455.21 ± 26.85 mseg and 44 ± 16.41 mseg, respectively).
  
  
  CONCLUSIONS
  This study confirmed an increase in the QTc interval and QTc dispersion associated with dialysis. That emphasizes the dependence of ventricular repolarization on fluid and electrolyte balance, and suggests a profile of higher vulnerability to arrhythmia associated with dialysis .
authors.affiliation: Centro Hospitalar Cova da Beira, Covilhã, Portugal. bruno.valentim@sapo.pt
authors.forename: Bruno
authors.initials: B
authors.lastname: Valentim
authors.forename: Alexandre
authors.initials: A
authors.lastname: Pereira
authors.forename: Patrícia
authors.initials: P
authors.lastname: Coelho
authors.forename: Telmo
authors.initials: T
authors.lastname: Pereira
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000517:prevention & control; D016009:Chi-Square Distribution; D016757:Death, Sudden, Cardiac / Q000517:prevention & control; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000473:pathology / Q000503:physiopathology*; D007676:Kidney Failure, Chronic / Q000503:physiopathology* / Q000628:therapy; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000009:adverse effects*; D013599:Systole / Q000502:physiology; D016276:Ventricular Function / Q000502:physiology*