title: Complex autonomic dysfunction in cardiovascular, intensive care, and schizophrenic patients assessed by autonomic information flow.
abstract: BACKGROUND
  The cardiovascular control system is mediated by mechanisms acting at different time scales, such as heart period, vagal, sympathetic, and other slower controllers. Since these elements are interrelated in a complex manner, classical control theory fails and information-based description, based on autonomic information flow (AIF) functions, is appropriate. We investigated the hypothesis that AIF functions of typical time scales specifically characterize autonomic dysfunction and prognosis.
  
  
  METHODS
  Holter recordings of patients with multiple organ dysfunction syndrome (MODS) (26 survivors, 10 non-survivors), heart failure (13 low risk, 13 high risk of cardiac arrest), idiopathic dilated cardiomyopathy (IDC) (26 low risk, 11 high risk), after abdominal aorta surgery (AAS) [32 with length of stay in hospital (LOS) >7 days; 62 with LOS < or =7 days] or with schizophrenia (n=20) were assessed and compared to 20 control subjects.
  
  
  RESULTS
  We found different AIF time scales discriminating risk. AIF measures of heart beat period had predominant prognostic value in heart failure patients, those of vagal communication in MODS and IDC, and those of long-term communication after AAS. Schizophrenic patients were discriminated from controls by vagally mediated communication.
  
  
  CONCLUSIONS
  Different time scales of AIF represent specific pathophysiological aspects of altered complex autonomic control (communication) and consequently have predictive implications.
authors.affiliation: Biomagnetic Center, Department of Neurology, Friedrich Schiller University, Jena, Germany. dirk.hoyer@biomag.uni-jena.de
authors.forename: Dirk
authors.initials: D
authors.lastname: Hoyer
authors.forename: Birgit
authors.initials: B
authors.lastname: Frank
authors.forename: Christine
authors.initials: C
authors.lastname: Götze
authors.forename: Hendrik
authors.initials: H
authors.lastname: Schmidt
authors.forename: Rafal
authors.initials: R
authors.lastname: Baranowski
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Zebrowski
authors.forename: Montserrat
authors.initials: M
authors.lastname: Vallverdú
authors.forename: Pere
authors.initials: P
authors.lastname: Caminal
authors.forename: Antonio
authors.initials: A
authors.lastname: Bayés De Luna
authors.forename: Kathrin
authors.initials: K
authors.lastname: Falkenhahn
authors.forename: Karl-Jürgen
authors.initials: KJ
authors.lastname: Bär
authors.forename: Phyllis K
authors.initials: PK
authors.lastname: Stein
mesh_terms: D001341:Autonomic Nervous System / Q000503:physiopathology*; D001342:Autonomic Nervous System Diseases / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D001683:Biological Clocks; D003422:Critical Care; D003936:Diagnosis, Computer-Assisted / Q000379:methods; D004562:Electrocardiography / Q000379:methods; D006333:Heart Failure / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D016247:Information Storage and Retrieval / Q000379:methods; D008297:Male; D009102:Multiple Organ Failure / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D012559:Schizophrenia / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*