title: Influence of bronchial blood flow and conductance on pulmonary function in stable systolic heart failure.
abstract: BACKGROUND
  The aim of this study was to determine the relationship between airway blood flow (Q(aw)), airway conductance (G(f-aw)) and pulmonary function in patients with stable HF.
  
  
  METHODS
  12 controls (CTRL: age=63±9 years, FVC=98±15%pred, LVEF=61±6%) (all data presented as mean±SD), 16 patients with mild HF (HF-A, NYHA I-II: age=64±9 years, FVC=90±17%pred, LVEF=28±6%), and 14 patients with moderate/severe HF (HF-B, NYHA III-IV: age=65±6 years, FVC=84±12%pred, LVEF=26±6%) were studied. Q(aw) was assessed using soluble gas measurements; perfusion pressure across airway bed (ΔP(aw)) was estimated from systemic and pulmonary pressure measurements; G(f-aw) was calculated as Q(aw)/ΔP(aw); PF was assessed by spirometry.
  
  
  RESULTS
  While Q˙(aw) was not significantly different between CTRL (61.3±17.9 μL min(-1)mL(-1)), HF-A (70.1±26.9 μL min(-1)mL(-1)) and HF-B (56.2±14.9 μL min(-1)mL(-1)) groups, G(f-aw), was elevated in HF-A (1.1±0.4 μL min(-1)mL(-1)mm Hg(-1), p<0.03) and tended to be elevated in HF-B (1.2±0.6 μL min(-1)mL(-1)mm Hg(-1), p=0.07) when compared to CTRL (0.8±0.3 μL min(-1)mL(-1)mm Hg(-1)). Significant positive correlations were found between G(f-aw) and RV/TLC for HF-A (r=0.63, p<0.02) and HF-B (r=0.58, p<0.05).
  
  
  CONCLUSIONS
  These results support the hypothesis that increased bronchial conductance and bronchial congestion may be related to greater small airway obstruction and as such may play a role in the PF abnormalities and symptoms of congestion commonly observed in HF patients.
authors.affiliation: Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Maile L
authors.initials: ML
authors.lastname: Ceridon
authors.forename: Norman R
authors.initials: NR
authors.lastname: Morris
authors.forename: Minelle L
authors.initials: ML
authors.lastname: Hulsebus
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Olson
authors.forename: Sophie
authors.initials: S
authors.lastname: Lalande
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Johnson
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000502:physiology; D001980:Bronchi / Q000098:blood supply*; D016022:Case-Control Studies; D004452:Echocardiography / Q000379:methods; D005260:Female; D054143:Heart Failure, Systolic / Q000473:pathology* / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011652:Pulmonary Circulation / Q000502:physiology*; D012129:Respiratory Function Tests; D013147:Spirometry / Q000379:methods; D014797:Vital Capacity / Q000502:physiology