Document Detail


Improvement of alveolar-capillary membrane diffusing capacity with exercise training in chronic heart failure.
MedLine Citation:
PMID:  15220300     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Chronic heart failure (CHF) may impair lung gas diffusion, an effect that contributes to exercise limitation. We investigated whether diffusion improvement is a mechanism whereby physical training increases aerobic efficiency in CHF. Patients with CHF (n = 16) were trained (40 min of stationary cycling, 4 times/wk) for 8 wk; similar sedentary patients (n = 15) were used as controls. Training increased lung diffusion (DlCO, +25%), alveolar-capillary conductance (DM, +15%), pulmonary capillary blood volume (VC, +10%), peak exercise O2 uptake (peak VO2, +13%), and VO2 at anaerobic threshold (AT, +20%) and decreased the slope of exercise ventilation to CO2 output (VE/VCO2, -14%). It also improved the flow-mediated brachial artery dilation (BAD, from 4.8 +/- 0.4 to 8.2 +/- 0.4%). These changes were significant compared with baseline and controls. Hemodynamics were obtained in the last 10 patients in each group. Training did not affect hemodynamics at rest and enhanced the increase of cardiac output (+226 vs. +187%) and stroke volume (+59 vs. +49%) and the decrease of pulmonary arteriolar resistance (-28 vs. -13%) at peak exercise. Hemodynamics were unchanged in controls after 8 wk. Increases in DlCO and DM correlated with increases in peak VO2 (r = 0.58, P = 0.019 and r = 0.51, P = 0.04, respectively) and in BAD (r = 0.57, P < 0.021 and r = 0.50, P = 0.04, respectively). After detraining (8 wk), DlCO, DM, VC, peak VO2, VO2 at AT, VE/VCO2 slope, cardiac output, stroke volume, pulmonary arteriolar resistance at peak exercise, and BAD reverted to levels similar to baseline and to levels similar to controls. Results document, for the first time, that training improves DlCO in CHF, and this effect may contribute to enhancement of exercise performance.
Authors:
Marco Guazzi; Giuseppe Reina; Gabriele Tumminello; Maurizio D Guazzi
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2004-06-25
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  97     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2004 Nov 
Date Detail:
Created Date:  2004-10-11     Completed Date:  2005-02-25     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1866-73     Citation Subset:  IM    
Affiliation:
Cardiopulmonary Laboratory, Cardiology Division, University of Milan, San Paolo Hospital, Via A. di Rudinì, 8, 20142 Milan, Italy. marco.guazzi@unimi.it
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MeSH Terms
Descriptor/Qualifier:
Bicycling
Blood Volume
Brachial Artery / physiopathology
Capillaries / physiopathology
Cardiac Output
Cardiac Output, Low / physiopathology*
Chronic Disease
Humans
Male
Middle Aged
Oxygen Consumption
Physical Education and Training*
Pulmonary Alveoli / physiopathology
Pulmonary Circulation
Pulmonary Diffusing Capacity*
Regional Blood Flow
Stroke Volume
Vascular Resistance
Vasodilation

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


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