| Differential contribution of dead space ventilation and low arterial pCO2 to exercise hyperpnea in patients with chronic heart failure secondary to ischemic or idiopathic dilated cardiomyopathy. | |
| | |
MedLine Citation:
|
PMID: 14759381 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
In chronic heart failure (CHF), the abnormally large ventilatory response to exercise (VE/VCO(2) slope) has 2 conceptual elements: the requirement of restraining arterial partial pressure of carbon dioxide (pCO(2)) from increasing (because of an increased ratio between increased physiologic dead space and tidal volume [VD/VT]) and the depression of arterial pCO(2) by further increased ventilation, which necessarily implies an important non-carbon dioxide stimulus to ventilation. We aimed to assess the contribution of these 2 factors in determining the elevated VE/VCO(2) slope in CHF. Thirty patients with CHF underwent cardiopulmonary exercise testing (age 65 +/- 11 years, left ventricular ejection fraction 34 +/- 15%, peak oxygen uptake 15.2 +/- 4 ml/kg/min, VE/VCO(2) slope 36.4). At rest and during exercise, arterial pCO(2) was measured and VD was calculated and separated into serial and alveolar components. VD/VT decreased from 0.57 at rest to 0.44 at peak exercise (p <0.01). VE/VCO(2) slope was correlated with peak exercise VD/VT (r = 0.67), the serial VD/VT ratio (r = 0.64), and alveolar VD/VT ratio (r = 0.51) at peak exercise (all p <0.01). VE/VCO(2) slope was also correlated with arterial pCO(2) (r = -0.75, p <0.001). Despite this, arterial pCO(2) was not related to peak oxygen uptake (r = 0.2) or to arterial lactate (r = -0.25) and only weakly to New York Heart Association functional class (F = 3.7). First, the increased VE/VCO(2) slope was caused by both the high VD/VT ratio and by other mechanisms, as shown by low arterial pCO(2) during exercise. Second, this latter component (depression of arterial pCO(2)) was not related to conventional measures of heart failure severity. |
| | |
Authors:
|
Roland Wensel; Panagiota Georgiadou; Darrel P Francis; Stephanie Bayne; Adam C Scott; Sabine Genth-Zotz; Stefan D Anker; Andrew J S Coats; Massimo F Piepoli |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: The American journal of cardiology Volume: 93 ISSN: 0002-9149 ISO Abbreviation: Am. J. Cardiol. Publication Date: 2004 Feb |
Date Detail:
|
Created Date: 2004-02-04 Completed Date: 2004-03-16 Revised Date: 2006-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 0207277 Medline TA: Am J Cardiol Country: United States |
Other Details:
|
Languages: eng Pagination: 318-23 Citation Subset: AIM; IM |
Affiliation:
|
Department of Clinical Cardiology, National Heart & Lung Institute, Imperial College of Science, Technology and Medicine, London, United Kingdom. roland.wensel@klinik.uni-regensburg.de |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Acidosis, Respiratory
/
etiology,
physiopathology* Aged Blood Gas Analysis Carbon Dioxide / physiology* Cardiomyopathy, Dilated / etiology, physiopathology* Exercise Test Female Humans Hypercapnia / etiology*, physiopathology Male Middle Aged Myocardial Ischemia / complications, physiopathology* Partial Pressure Pulmonary Alveoli / physiopathology Pulmonary Ventilation / physiology Respiratory Dead Space / physiology* |
| Chemical | |
Reg. No./Substance:
|
124-38-9/Carbon Dioxide |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Usefulness of periprocedural creatinine phosphokinase-MB release to predict adverse outcomes after i...
Next Document: Usefulness of tissue Doppler imaging for estimation of filling pressures in patients with primary or...