title: Identification of vascular responses to exercise and orthostatic stress in bed rest-induced cardiovascular deconditioning.
abstract: In this paper, the effects of bed rest-induced cardiovascular deconditioning were investigated by means of a previously developed multivariate model for the assessment of arterial control of circulation. The vascular response to exercise and tilt, before and after a 14-day head down tilt bed rest, was identified and disentangled from the main mechanisms due to global, neural control of circulation. Results of the decomposition of diastolic pressure and pulse pressure beat-by-beat series and the relevant spectral analysis suggested that the autoregulation-related response is not affected by prolonged exposition to microgravity. As to the complex regulation of arterial blood pressure, a maintained responsiveness to sympathetic stimuli was found, even in presence of indications of the cardiovascular deconditioning, such as tachycardia, reset of baroreflex, cardiopulmonary unloading. These preliminary results emphasized the necessity for more complex analyses of the main alterations and compensatory mechanisms elicited by microgravity-induced-cardiovascular deconditioning, in order to develop more effective long term strategies to prevent it.
authors: Dipartimento di Bioingegneria, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy. federico.aletti@polimi.it
authors: Federico
authors: F
authors: Aletti
authors: Manuela
authors: M
authors: Ferrario
authors: Enrico
authors: E
authors: Tam
authors: Michela
authors: M
authors: Cautero
authors: Sergio
authors: S
authors: Cerutti
authors: Carlo
authors: C
authors: Capelli
authors: Giuseppe
authors: G
authors: Baselli
mesh_terms: D001510:Bed Rest; D001794:Blood Pressure / Q000502:physiology*; D018493:Cardiovascular Deconditioning / Q000502:physiology*; D003971:Diastole / Q000502:physiology; D004244:Dizziness / Q000503:physiopathology*; D015444:Exercise; D018475:Head-Down Tilt / Q000502:physiology; D006801:Humans; D015999:Multivariate Analysis; D013599:Systole / Q000502:physiology; D055815:Young Adult