title: Heart rate variability and baroreceptor sensitivity in acute stroke: a systematic review.
abstract: BACKGROUND
  Autonomic nervous system dysfunction is common after acute stroke and is associated with elevated risk of cardiac arrhythmia and mortality. Heart rate variability and baroreceptor sensitivity have been investigated as parameters of autonomic nervous system dysfunction for the prediction of stroke outcome.
  
  
  CONCLUSIONS
  We performed a systematic literature review on heart rate variability and baroreceptor sensitivity as parameters for autonomic nervous function in acute stroke. Twenty-two studies were included. Associations between heart rate variability or baroreceptor sensitivity and stroke severity, early and late complications, dependency and mortality were reported. However, interpretability of most studies and extrapolation to general stroke population are limited due to many confounding factors such as varying methodology, small sample sizes, survival selection, and exclusion of patients with frequently occurring comorbidities in stroke. Key issues, such as the effect of thrombolytic therapy on autonomic function, autonomic nervous system dysfunction in the hyperacute phase of stroke, and correlation with the risk of recurrent stroke have not been investigated. Also, nonlinear techniques have remained largely unexplored in this domain, in spite of their advantage to provide more solid evaluation in the occurrence of arrhythmia.
  
  
  CONCLUSIONS
  Cardiac autonomic dysfunction, represented by reduced heart rate variability or impaired baroreceptor sensitivity, is associated with stroke severity, early and late complications, dependency, and mortality. Large-scale prospective studies applying internationally accepted standards of measures for analysis of heart rate variability and baroreceptor sensitivity are needed in patients with acute stroke.
authors.affiliation: Department of Neurology, Universitair Ziekenhuis Antwerpen, Antwerp, Belgium.|Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium.
authors.forename: Laetitia
authors.identifier: http://orcid.org/0000-0002-5503-5724
authors.initials: L
authors.lastname: Yperzeele
authors.affiliation: Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium.|Department of Neurology, Universitair Ziekenhuis Brussel, Brussels, Belgium.
authors.forename: Robbert-Jan
authors.initials: RJ
authors.lastname: van Hooff
authors.affiliation: Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium.|Department of Neurology, Universitair Ziekenhuis Brussel, Brussels, Belgium.|National MS Center, Melsbroek, Belgium.
authors.forename: Guy
authors.initials: G
authors.lastname: Nagels
authors.affiliation: Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium.|Department of Neurology, Universitair Ziekenhuis Brussel, Brussels, Belgium.
authors.forename: Ann
authors.initials: A
authors.lastname: De Smedt
authors.affiliation: Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium.|Department of Neurology, Universitair Ziekenhuis Brussel, Brussels, Belgium.|Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Jacques
authors.initials: J
authors.lastname: De Keyser
authors.affiliation: Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium.|Department of Neurology, Universitair Ziekenhuis Brussel, Brussels, Belgium.
authors.forename: Raf
authors.initials: R
authors.lastname: Brouns
mesh_terms: D017704:Baroreflex / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D011311:Pressoreceptors / Q000503:physiopathology*; D020521:Stroke / Q000503:physiopathology*
keywords: acute; autonomic function; baroreflex; heart rate variability, stroke