title: Effect of β2-adrenergic receptor stimulation on lung fluid in stable heart failure patients.
abstract: BACKGROUND
  The purpose of this study was to determine: (1) whether stable heart failure patients with reduced ejection fraction (HFrEF) have elevated extravascular lung water (EVLW) when compared with healthy control subjects; and (2) the effect of acute β2-adrenergic receptor (β2AR) agonist inhalation on lung fluid balance.
  
  
  METHODS
  Twenty-two stable HFrEF patients and 18 age- and gender-matched healthy subjects were studied. Lung diffusing capacity for carbon monoxide (DLCO), alveolar-capillary membrane conductance (DmCO), pulmonary capillary blood volume (Vc) (via re-breathe) and lung tissue volume (Vtis) (via computed tomography) were assessed before and within 30 minutes after administration of nebulized albuterol. EVLW was derived as Vtis- Vc.
  
  
  RESULTS
  Before administration of albuterol, Vtisand EVLW were higher in HFrEF vs control (998 ± 200 vs 884 ± 123 ml, p = 0.041; and 943 ± 202 vs 802 ± 133 ml, p = 0.015, respectively). Albuterol decreased Vtisand EVLW in HFrEF patients (-4.6 ± 7.8%, p = 0.010; -4.6 ± 8.8%, p = 0.018) and control subjects (-2.8 ± 4.9%, p = 0.029; -3.0 ± 5.7%, p = 0.045). There was an inverse relationship between pre-albuterol values and pre- to post-albuterol change for EVLW (r2= -0.264, p = 0.015) and DmCO(r2= -0.343, p = 0.004) in HFrEF only.
  
  
  CONCLUSIONS
  Lung fluid is elevated in stable HFrEF patients relative to healthy subjects. Stimulation of β2ARs may cause fluid removal in HFrEF, especially in patients with greater evidence of increased lung water at baseline.
authors.affiliation: Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, UK; Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA. Electronic address: b.j.taylor@leeds.ac.uk.
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: Taylor
authors.affiliation: School of Kinesiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Snyder
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Maile L
authors.initials: ML
authors.lastname: Richert
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Courtney M
authors.initials: CM
authors.lastname: Wheatley
authors.affiliation: Division of Cardiovascular Diseases, Mayo Graduate School, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Steven C
authors.initials: SC
authors.lastname: Chase
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Lyle J
authors.initials: LJ
authors.lastname: Olson
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Johnson
mesh_terms: D000280:Administration, Inhalation; D058666:Adrenergic beta-2 Receptor Agonists / Q000627:therapeutic use*; D000368:Aged; D000420:Albuterol / Q000627:therapeutic use*; D016022:Case-Control Studies; D015633:Extravascular Lung Water / Q000187:drug effects*; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011653:Pulmonary Diffusing Capacity
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D000420:Albuterol
keywords: albuterol; alveolar-capillary membrane conductance; computed tomography; lung diffusing capacity; pulmonary edema