| Perfusion/ventilation mismatch during exercise in chronic heart failure: an investigation of circulatory determinants. | |
| | |
MedLine Citation:
|
PMID: 7662449 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
BACKGROUND: The ventilatory cost of carbon dioxide (CO2) elimination on exercise (VE/VCO2) is increased in chronic heart failure (CHF). This reflects increased physiological dead space ventilation secondary to mismatching between perfusion and ventilation during exercise. The objectives of this study were to investigate the relation of this increased VE/VCO2 slope to the syndrome of CHF or to limitation of the exercise related increase of pulmonary blood flow, or both. PATIENTS AND METHODS: Maximal treadmill exercise tests with respiratory gas analysis were performed in 45 patients with CHF (defined as resting left ventricular ejection fraction < 40% on radionuclide scan); 15 normal controls; 23 patients with coronary artery disease and normal resting left ventricular function; and 13 pacemaker dependent patients (six with and seven without CHF) directly comparing exercise responses in rate responsive and fixed rate mode. RESULTS: Patients with CHF had a steeper VE/VCO2 slope than normal controls: this was related inversely to peak VO2 below 20 mol/min/kg. In patients with coronary artery disease in whom peak VO2 (at respiratory exchange ratio > 1) was as limited as in the patients with CHF but resting left ventricular function was normal, the VE/VCO2 slope was normal. In pacemaker dependent patients fixed rate pacing resulted in lower exercise capacity and peak VO2 than rate responsive pacing; the VE/VCO2 slope was normal in patients without CHF but steeper than normal in patients with CHF; the VE/VCO2 slope was steeper during fixed rate than during rate responsive pacing in these patients with CHF. CONCLUSIONS: These findings suggest that the perfusion/ventilation mismatch during exercise in CHF is related to the chronic consequences of the syndrome and not directly to limitation of exercise related pulmonary flow. Only when the syndrome of CHF is present can matching between perfusion and ventilation be acutely influenced by changes in pulmonary flow. |
| | |
Authors:
|
A P Banning; N P Lewis; D B Northridge; J S Elborn; A H Hendersen |
Related Documents
:
|
12163219 - Chronic heart failure and skeletal muscle catabolism: effects of exercise training. 16799239 - Effect of physical training on insulin resistance in patients with chronic heart failure. 11896019 - Exercise training normalizes altered calcium-handling proteins during development of he... 9799209 - Skeletal muscle metabolism limits exercise capacity in patients with chronic heart fail... 11005589 - Inefficient ventilation and reduced respiratory muscle capacity in congestive heart fai... 16338939 - Enhanced prognostic value from cardiopulmonary exercise testing in chronic heart failur... 10589859 - Increased fat availability enhances the capacity of trained individuals to perform prol... 20424399 - Is exercise adherence associated with clinical outcomes in patients with advanced heart... 937989 - Heart volume and physical fitness of parturients. |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: British heart journal Volume: 74 ISSN: 0007-0769 ISO Abbreviation: Br Heart J Publication Date: 1995 Jul |
Date Detail:
|
Created Date: 1995-10-06 Completed Date: 1995-10-06 Revised Date: 2010-03-24 |
Medline Journal Info:
|
Nlm Unique ID: 0370634 Medline TA: Br Heart J Country: ENGLAND |
Other Details:
|
Languages: eng Pagination: 27-33 Citation Subset: AIM; IM |
Affiliation:
|
Department of Cardiology, University of Wales College of Medicine, Cardiff. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adult Aged Carbon Dioxide / blood Cardiac Pacing, Artificial Chronic Disease Coronary Disease / physiopathology Exercise Test* Female Heart Failure / physiopathology* Humans Male Middle Aged Oxygen / blood Oxygen Consumption / physiology Partial Pressure Pulmonary Gas Exchange / physiology* Ventricular Function, Left / physiology |
| Chemical | |
Reg. No./Substance:
|
124-38-9/Carbon Dioxide; 7782-44-7/Oxygen |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Baroreflex sensitivity and neurohormonal activation in patients with acute myocardial infarction.
Next Document: Cross sectional profiles of systolic flow velocities in left ventricular outflow tract of normal sub...