title: Analysis of heart-rate variability: a noninvasive predictor of death and poor outcome in patients with severe head injury.
abstract: BACKGROUND
  Analysis of heart-rate variability (HRV) is a promising new technique for noninvasive quantification of autonomic function. We measured HRV in patients with severe head injury to assess its potential as a monitoring tool.
  
  
  METHODS
  Analysis of HRV was prospectively done on all intensive care unit patients. Concurrent data on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were collected. Registry data were reviewed to identify patients with severe head injury, defined as Head/Neck Abbreviated Injury Scale score > or = 4. Mortality, likelihood of discharge to home, ICP, and CPP were compared between patients with abnormal HRV and those without.
  
  
  RESULTS
  Low HRV was associated with increased mortality and decreased rate of discharge to home. Abnormal HRV was associated with episodes of increased ICP and decreased CPP.
  
  
  CONCLUSIONS
  Assessment of HRV is a noninvasive method that can be widely used. Abnormal HRV was associated with poor outcome and altered cerebral perfusion. Monitoring of HRV may improve outcome by allowing earlier detection and treatment of intracranial pathology.
authors.affiliation: Department of Surgery, University of California, San Diego, 92103-8896 USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Winchell
authors.forename: D B
authors.initials: DB
authors.lastname: Hoyt
mesh_terms: D015998:Abbreviated Injury Scale; D002560:Cerebrovascular Circulation; D006259:Craniocerebral Trauma / Q000401:mortality / Q000503:physiopathology*; D004562:Electrocardiography / Q000592:standards*; D006339:Heart Rate; D006801:Humans; D007427:Intracranial Pressure; D008991:Monitoring, Physiologic; D010351:Patient Discharge; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D015203:Reproducibility of Results; D012307:Risk Factors; D012815:Signal Processing, Computer-Assisted; D016019:Survival Analysis