Positive and negative feedback mechanisms in the neural regulation of cardiovascular function in healthy and spinal cord-injured humans

J. M. Legramante, G. Raimondi, M. Massaro, F. Iellamo

Research output: Contribution to journalArticle

Abstract

Background - We tested the hypothesis that in humans, hypertension/tachycardia and hypotension/bradycardia nonbaroreflex sequences that occur within spontaneous arterial pressure (AP) and R-R interval fluctuations are an expression of positive feedback mechanisms neurally regulating the cardiovascular system. Methods and Results - We studied 15 spinal cord-injured (SCI) subjects (8 tetraplegics and 7 paraplegics) and 8 healthy subjects. The occurrence of nonbaroreflex (NBseq) and baroreflex (Bseq) sequences, ie, hypertension-bradycardia and hypotension-tachycardia sequences, was assessed during rest and head-up tilt (HUT). The ratio between Bseq and NBseq (B/NB ratio) was also calculated. In resting conditions, the occurrence of NBseq was significantly lower (P

Original languageEnglish
Pages (from-to)1250-1255
Number of pages6
JournalCirculation
Volume103
Issue number9
Publication statusPublished - Mar 6 2001

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Keywords

  • Baroreceptors
  • Nervous system, autonomic
  • Reflex

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine

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