Document Detail


Reduced alveolar-capillary membrane diffusing capacity in chronic heart failure. Its pathophysiological relevance and relationship to exercise performance.
MedLine Citation:
PMID:  7758183     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: The pulmonary diffusing capacity for carbon monoxide (DLCO) is reduced in chronic heart failure (CHF) and is an independent predictor of peak exercise oxygen uptake. The pathophysiological basis for this remains unknown. The aim of this study was to partition DLCO into its membrane conductance (DM) and capillary blood volume components (Vc) and to assess if alveolar-capillary membrane function correlated with functional status, exercise capacity, and pulmonary vascular resistance. METHODS AND RESULTS: The classic Roughton and Forster method of measuring single-breath DLCO at varying alveolar oxygen concentrations was used to determine DM and Vc in 15 normal subjects and 50 patients with CHF. All performed symptom-limited maximal bicycle exercise tests with respiratory gas analysis; 15 CHF patients underwent right heart catheterization. DLCO was significantly reduced in CHF patients compared with normal subjects, predominantly because of a reduction in DM (7.0 +/- 2.6 versus 12.9 +/- 3.8 versus 20.0 +/- 6.1 mmol.min-1.kPa-1 in New York Heart Association class III, class II, and normal subjects, respectively, P < .0001), even when the reduction in lung volumes was accounted for by the division of DM by the effective alveolar volume. The Vc component of DLCO was not impaired. DM significantly correlated with maximal exercise oxygen uptake (r = .72, P < .0001) and inversely correlated with pulmonary vascular resistance (r = .65, P < .01) in CHF. CONCLUSIONS: Reduced alveolar-capillary membrane diffusing capacity is the major component of impaired pulmonary gas transfer in CHF, correlating with maximal exercise capacity and functional status. DM may be a useful marker for the alveolar-capillary barrier damage induced by raised pulmonary capillary pressure.
Authors:
S Puri; B L Baker; D P Dutka; C M Oakley; J M Hughes; J G Cleland
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Circulation     Volume:  91     ISSN:  0009-7322     ISO Abbreviation:  Circulation     Publication Date:  1995 Jun 
Date Detail:
Created Date:  1995-06-23     Completed Date:  1995-06-23     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0147763     Medline TA:  Circulation     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  2769-74     Citation Subset:  AIM; IM    
Affiliation:
Department of Medicine (Clinical Cardiology and Respiratory Medicine), Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.
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MeSH Terms
Descriptor/Qualifier:
Blood-Air Barrier / physiology*
Capillary Permeability / physiology
Case-Control Studies
Exercise Test
Exercise Tolerance / physiology*
Female
Heart Catheterization
Heart Failure / diagnosis,  physiopathology*
Humans
Lung Volume Measurements
Male
Middle Aged
Pulmonary Circulation / physiology
Pulmonary Diffusing Capacity / physiology*
Pulmonary Gas Exchange / physiology
Vascular Resistance / physiology

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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