title: Influence of the metaboreflex on arterial blood pressure in heart failure patients.
abstract: BACKGROUND
  Feedback from active locomotor muscles contributes to the exercise pressor response in healthy humans, and is thought to be more prominent in heart failure (HF). The purpose of this study was to examine the influence of metaboreflex stimulation on arterial pressure in HF.
  
  
  METHODS
  Eleven HF patients (51 ± 5 years, New York Heart Association Class I/II, left ventricular ejection fraction 32 ± 3%) and 11 controls (42 ± 3 years) were recruited. Participants completed two exercise sessions on separate days: (1) symptom limited graded exercise test; and (2) constant work rate cycling (60% peak oxygen consumption,V˙O2) for 4 minutes with 2 minutes passive recovery. Recovery was randomized to normal or locomotor muscle regional circulatory occlusion (RCO). Mean arterial pressure (MAP), systolic pressure (SBP), diastolic pressure, heart rate (HR) and V˙O2 were measured at rest, end-exercise and recovery. O2 pulse (V˙O2/HR) and the rate pressure product (RPP = HR × SBP) were calculated.
  
  
  RESULTS
  In response to RCO, mean arterial pressure and SBP increased in HF compared with CTLs (6.8 ± 5.8% vs -3.0 ± 7.8%, P < .01 and 3.4 ± 6.4% vs -12.7 ± 10.4%, P < .01, respectively), with no difference in diastolic pressure (P = .61). HF patients had a smaller reduction in HR and RPP, but also displayed a larger decrease in O2 pulse consequent to locomotor metaboreflex stimulation (P < .05, for all).
  
  
  CONCLUSIONS
  RCO resulted in a markedly increased pressor response in HF relative to controls, due primarily to an increase of SBP and attenuated cardiac recovery as noted by the persistent elevation in HR.
authors.affiliation: Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN. Electronic address: keller.manda@mayo.edu.
authors.forename: Manda L
authors.initials: ML
authors.lastname: Keller-Ross
authors.affiliation: Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN.
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Johnson
authors.affiliation: Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Joyner
authors.affiliation: Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Olson
mesh_terms: D000328:Adult; D062186:Arterial Pressure / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D054143:Heart Failure, Systolic / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020127:Recovery of Function / Q000502:physiology*; D012720:Severity of Illness Index; D013318:Stroke Volume; D016277:Ventricular Function, Left / Q000502:physiology*