title: Interactions between short-term and long-term cardiovascular control mechanisms.
abstract: The cardiovascular system incorporates several controlling mechanisms acting as feedback loops over different time horizons. Because of their complex interrelationships, information-based methods such as autonomic information flow (AIF) functions promise to be useful in identifying normal and pathological behavior. Optimal adjustment between those controllers is necessary for healthy global behavior of the organism. We investigated the question as to whether there are typical relationships between short-term and long-term AIF by means of a meta-analysis of several of our own clinical studies of the mortality of patients with multiple organ dysfunction syndrome, heart failure, idiopathic dilated cardiomyopathy, and the length of stay in hospital after abdominal aorta surgery. We found a fundamental association of increased short-term randomness (decreased AIF) and decreased long-term randomness (increased AIF) due to pathology. A systems theoretic validation of this fundamental type of association was done by an appropriate mathematical model using a dissipative system with two feedback loops over different time horizons. The systematic simulation of an increasing collapse of the short feedback loop confirmed the inverse association between short-term and long-term information flow as a fundamental, system inherent type of readjustment that occurs under pathological conditions.
authors.affiliation: Biomagnetic Center, Department of Neurology, Friedrich Schiller University, 07740 Jena, Germany.
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: Phyllis K
authors.initials: PK
authors.lastname: Stein
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Zebrowski
authors.forename: Rafal
authors.initials: R
authors.lastname: Baranowski
authors.forename: Manuel
authors.initials: M
authors.lastname: Palacios
authors.forename: Montserrat
authors.initials: M
authors.lastname: Vallverdú
authors.forename: Pere
authors.initials: P
authors.lastname: Caminal
authors.forename: Anthony
authors.initials: A
authors.lastname: Bayés de Luna
authors.forename: Georg
authors.initials: G
authors.lastname: Schmidt
authors.forename: Hendrik
authors.initials: H
authors.lastname: Schmidt
mesh_terms: D001341:Autonomic Nervous System / Q000503:physiopathology*; D001683:Biological Clocks; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000503:physiopathology*; D003198:Computer Simulation; D003936:Diagnosis, Computer-Assisted / Q000379:methods; D004562:Electrocardiography / Q000379:methods*; D005246:Feedback; D006321:Heart / Q000294:innervation* / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008955:Models, Cardiovascular; D013997:Time Factors