title: Potentially detrimental cardiovascular effects of oxygen in patients with chronic left ventricular systolic dysfunction.
abstract: BACKGROUND
  Although the haemodynamic effects of oxygen in healthy subjects are well documented, there have been no well-controlled studies of the effects of oxygen in patients with heart failure (HF).
  
  
  OBJECTIVE
  To non-invasively evaluate haemodynamic and neurohumoral effects of oxygen in patients with HF at rest.
  
  
  RESULTS
  13 men with heart failure and left ventricular systolic dysfunction (LVSD) were randomised in a double-blind, placebo-controlled, crossover trial to receive medical air or oxygen (40% and high concentration via Hudson non-rebreathing mask). Haemodynamic measurements were made with applanation tonometry, impedance cardiography and venous occlusion plethysmography. Plasma C-terminal B-type natriuretic peptide and A-type natriuretic peptide were measured. Data were analysed with paired t tests. Cardiac output fell by -0.58 (0.62) l/min on high-flow oxygen compared with -0.02 (0.58) l/min on air, p=0.031. Oxygen caused a reduction in heart rate (-4.02 (4.21) vs 0.41 (5.35) beats/min, respectively, p=0.021) and a trend towards increased systemic vascular resistance (875 (1174) vs 235 (321) dyne/s/m(5), p=0.050). Oxygen led to a paradoxical increase in forearm blood flow (0.513 (0.391) vs 0.024 (0.246) ml/min/100 ml forearm volume on air, p=0.01). Natriuretic peptides were unchanged with oxygen.
  
  
  CONCLUSIONS
  High-concentration inhaled oxygen has significant haemodynamic effects in patients with LVSD and mild HF. Such effects may be detrimental in patients with decompensated HF.
authors.affiliation: British Heart Foundation Cardiovascular Research Centre, University of Glasgow, 126 University Place, Glasgow, UK.
authors.forename: James H
authors.initials: JH
authors.lastname: Park
authors.forename: Sean
authors.initials: S
authors.lastname: Balmain
authors.forename: Colin
authors.initials: C
authors.lastname: Berry
authors.forename: John J
authors.initials: JJ
authors.lastname: Morton
authors.forename: John J V
authors.initials: JJ
authors.lastname: McMurray
mesh_terms: D000368:Aged; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005542:Forearm / Q000098:blood supply; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D045265:Natriuretic Peptides / Q000378:metabolism; D010100:Oxygen / Q000009:adverse effects*; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology* / Q000628:therapy
chemical_list: D045265:Natriuretic Peptides; D010100:Oxygen