title: Predictors of haemodynamic instability and heart rate variability during haemodialysis.
abstract: BACKGROUND
  The pathogenesis of haemodialysis-induced hypotension is multifactorial and may include autonomic nervous system dysfunction. The present study was undertaken to (i) determine heart rate variability (HRV) in chronic haemodialysis patients without and with haemodynamic instability (hypotension-prone) during ultrafiltration and (ii) identify patients at risk and the predictors of dialysis-related hypotension.
  
  
  METHODS
  HRV was evaluated in 56 chronic haemodialysis patients without (stable; n = 27) and with symptomatic hypotension episodes (unstable; n = 29) during daytime, haemodialysis and night-time periods. Logistic regression analysis was performed in a model that included clinical and biochemical data and HRV measurements.
  
  
  RESULTS
  HRV was significantly reduced in haemodynamically unstable as compared with the stable patients. LF/HF ratio, an index representative of sympathovagal balance, was significantly lower in unstable patients, especially in those with ischaemic heart disease and diabetes mellitus. In a logistic regression model including clinical data and HRV measurements, ischaemic heart disease and left ventricular systolic dysfunction were found to be the main predictors of haemodynamic instability.
  
  
  CONCLUSIONS
  These data suggest that haemodynamic instability is strongly associated with a decreased HRV and an impaired sympathovagal balance, suggesting disturbed autonomic control in uraemic patients with cardiac damage. Patients with ischaemic heart disease, reduced left ventricular systolic function and decreased HRV may be at the highest risk to be haemodynamically unstable during haemodialysis. The role of early detection and treatment of ischaemic heart disease in preventing symptomatic hypotensive episodes in these patients remains to be determined.
authors.affiliation: Nephrology and Hypertension Services, Hadassah University Hospital, POB 12000, Jerusalem 91120, Israel. rdvora@hadassah.org.il
authors.forename: Dvora
authors.initials: D
authors.lastname: Rubinger
authors.forename: Nina
authors.initials: N
authors.lastname: Revis
authors.forename: Arthur
authors.initials: A
authors.lastname: Pollak
authors.forename: Myron H
authors.initials: MH
authors.lastname: Luria
authors.forename: Dan
authors.initials: D
authors.lastname: Sapoznikov
mesh_terms: D015897:Comorbidity; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006440:Hemofiltration; D006801:Humans; D007022:Hypotension / Q000209:etiology; D007676:Kidney Failure, Chronic / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000453:epidemiology / Q000503:physiopathology; D013564:Sympathetic Nervous System / Q000503:physiopathology; D018487:Ventricular Dysfunction, Left / Q000453:epidemiology / Q000503:physiopathology