Document Detail

Ventilatory assistance improves exercise endurance in stable congestive heart failure.
MedLine Citation:
PMID:  10588589     Owner:  NLM     Status:  MEDLINE    
We postulated that ventilatory assistance during exercise would improve cardiopulmonary function, relieve exertional symptoms, and increase exercise endurance (T(lim)) in patients with chronic congestive heart failure (CHF). After baseline pulmonary function tests, 12 stable patients with advanced CHF (ejection fraction, 24 +/- 3% [mean +/- SEM]) performed constant-load exercise tests at approximately 60% of their predicted maximal oxygen consumption (V O(2)max) while breathing each of control (1 cm H(2)O), continuous positive airway pressure optimized to the maximal tolerable level (CPAP = 4.8 +/- 0.2 cm H(2)O) or inspiratory pressure support (PS = 4.8 +/- 0.2 cm H(2)O), in randomized order. Measurements during exercise included cardioventilatory responses, esophageal pressure (Pes), and Borg ratings of dyspnea and leg discomfort (LD). At a standardized time near end-exercise, PS and CPAP reduced the work of breathing per minute by 39 +/- 8 and 25 +/- 4%, respectively (p < 0. 01). In response to PS: T(lim) increased by 2.8 +/- 0.8 min or 43 +/- 14% (p < 0.01); slopes of LD-time, V O(2)-time, V CO(2)-time, and tidal Pes-time decreased by 24 +/- 10, 20 +/- 11, 28 +/- 8, and 44 +/- 9%, respectively (p < 0.05); dyspnea and other cardioventilatory parameters did not change. CPAP did not significantly alter measured exercise responses. The increase in T(lim) was explained primarily by the decrease in LD- time slopes (r = -0.71, p < 0.001) which, in turn, correlated with the reductions in V O(2)-time (r = 0.61, p < 0.01) and tidal Pes-time (r = 0.52, p < 0.01). in conclusion, ventilatory muscle unloading with PS reduced exertional leg discomfort and increased exercise endurance in patients with stable advanced CHF.
D E O'Donnell; C D'Arsigny; S Raj; H Abdollah; K A Webb
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Publication Detail:
Type:  Clinical Trial; Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  American journal of respiratory and critical care medicine     Volume:  160     ISSN:  1073-449X     ISO Abbreviation:  Am. J. Respir. Crit. Care Med.     Publication Date:  1999 Dec 
Date Detail:
Created Date:  2000-04-03     Completed Date:  2000-04-03     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  9421642     Medline TA:  Am J Respir Crit Care Med     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1804-11     Citation Subset:  AIM; IM    
Respiratory Investigation Unit, Department of Medicine, Queen's University, Kingston, Ontario, Canada.
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MeSH Terms
Double-Blind Method
Dyspnea / etiology
Exercise Tolerance*
Heart Failure / physiopathology*,  therapy
Intermittent Positive-Pressure Ventilation
Lung Volume Measurements
Middle Aged
Oxygen Consumption
Pain / etiology
Positive-Pressure Respiration*
Respiratory Mechanics

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

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