title: T-Wave Alternans, Heart Rate Turbulence, and Ventricular Ectopy in Standard versus Daily Hemodialysis: Results from the FHN Daily Trial.
abstract: BACKGROUND
  Hemodialysis (HD) patients are at high risk of sudden cardiac death (SCD). HD 6-times/week (6x/wk) may reduce SCD risk compared to usual 3-times/week HD (3x/wk) by mechanisms unknown. T-wave alternans (TWA), heart rate turbulence (HRT), and ventricular ectopy (VE) are elevated in HD patients, but their response to 6x/wk HD has not been assessed.
  
  
  METHODS
  Baseline and 1-year Holter recordings were analyzed from enrollees in the Frequent Hemodialysis Network Daily Trial, a randomized trial comparing 3x/wk to 6x/wk in 245 chronic HD patients. TWA, HRT, and VE were assessed using MARS software.
  
  
  RESULTS
  Sixty-eight patients (34 with 6x/wk) had complete baseline and 1-year Holter recordings. Mean age was 50 ± 13 years and 38% were female. Maximum TWA in the 3x/wk and 6x/wk groups were 52.4 μV at baseline and 51.2 μV at 1-year versus 54.0 and 49.9 μV, respectively (P = 0.28). The proportion of abnormal HRT (scores of 1 or 2) in the 3x/wk group decreased from 65% to 56% at 1-year versus 53% to 53% in the 6x/wk group (P = 0.58). Mean %VE changed from 1.6% to 2.9% in the 3x/wk group from baseline to 1-year and from 2.1% to 3.7% in the 6x/wk group (P = 0.85).
  
  
  CONCLUSIONS
  There were no significant differences in HRT or VE at 1-year in chronic HD patients randomized to 6x/wk versus 3x/wk and a trend in TWA reduction. Additional studies are needed to evaluate the impact and mechanisms of SCD in HD.
authors: Northwestern University, Feinberg School of Medicine, Chicago, IL.
authors: Rachel M
authors: RM
authors: Kaplan
authors: Hennepin County Medical Center, University of Minnesota, Minneapolis, MN.
authors: Charles A
authors: CA
authors: Herzog
authors: Cleveland Clinic, Cleveland, OH.
authors: Brett
authors: B
authors: Larive
authors: Northwestern University, Feinberg School of Medicine, Chicago, IL.
authors: Haris
authors: H
authors: Subacius
authors: Beth Israel Deaconess Medical Center, Boston, MA.
authors: Bruce D
authors: BD
authors: Nearing
authors: Beth Israel Deaconess Medical Center, Boston, MA.
authors: Richard
authors: R
authors: Verrier
authors: Northwestern University, Feinberg School of Medicine, Chicago, IL. r-passman@northwestern.edu.
authors: Rod S
authors: RS
authors: Passman
mesh_terms: D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D016757:Death, Sudden, Cardiac / Q000209:etiology; D015716:Electrocardiography, Ambulatory; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000009:adverse effects*; D012307:Risk Factors; D018879:Ventricular Premature Complexes / Q000503:physiopathology*
keywords: T-wave alternans; dialysis; heart rate turbulence; sudden cardiac death