title: Norepinephrine remains increased in the six-minute walking test after heart transplantation.
abstract: OBJECTIVE
  We sought to evaluate the neurohormonal activity in heart transplant recipients and compare it with that in heart failure patients and healthy subjects during rest and just after a 6-minute walking test.
  
  
  BACKGROUND
  Despite the improvements in quality of life and survival provided by heart transplantation, the neurohormonal profile is poorly described.
  
  
  METHODS
  Twenty heart transplantation (18 men, 49+/-11 years and 8.5+/-3.3 years after transplantation), 11 heart failure (8 men, 43+/-10 years), and 7 healthy subjects (5 men 39+/-8 years) were included in this study. Blood samples were collected immediately before and during the last minute of the exercise.
  
  
  RESULTS
  During rest, patients' norepinephrine plasma level (659+/-225 pg/mL) was higher in heart transplant recipients (463+/-167 pg/mL) and healthy subjects (512+/-132), p<0.05. Heart transplant recipient's norepinephrine plasma level was not different than that of healthy subjects. Just after the 6-minute walking test, the heart transplant recipient's norepinephrine plasma level (1248+/-692 pg/mL) was not different from that of heart failure patients (1174+/-653 pg/mL). Both these groups had a higher level than healthy subjects had (545+/-95 pg/mL), p<0.05.
  
  
  CONCLUSIONS
  Neurohormonal activity remains increased after the 6-minute walking test after heart transplantation.
authors.affiliation: Instituto do Coração, Hospital das Clínicas, Universidade de São Paulo, Brazil. gvguima@usp.br
authors.forename: Guilherme Veiga
authors.initials: GV
authors.lastname: Guimarães
authors.forename: Veridiana
authors.initials: V
authors.lastname: D'Avila
authors.forename: Edimar Alcides
authors.initials: EA
authors.lastname: Bocchi
authors.forename: Vitor Oliveira
authors.initials: VO
authors.lastname: Carvalho
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000601:surgery; D016027:Heart Transplantation / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood*; D016138:Walking / Q000502:physiology*
chemical_list: D009638:Norepinephrine