Physiological cardiac reserve: development of a non-invasive method and first estimates in man.
Heart
; 79(3): 289-94, 1998 Mar.
Article
em En
| MEDLINE
| ID: mdl-9602665
ABSTRACT
OBJECTIVE:
To investigate whether physiological cardiac reserve can be measured in man without invasive procedures and whether it is a major determinant of exercise capacity.DESIGN:
Development of method of measurement and an observational study.SETTING:
A regional cardiothoracic centre.SUBJECTS:
70 subjects with a wide range of cardiac function, from heart failure patients to athletes.METHODS:
Subjects underwent treadmill, symptom limited cardiopulmonary exercise tests to measure aerobic exercise capacity (represented by VO2max) and cardiac reserve. Cardiac output was measured non-invasively using the CO2 rebreathing technique.RESULTS:
Cardiac power output (CPOmax) at peak exercise was found to be significantly related to aerobic capacity CPOmax (W) = 0.35 + 1.5 VO2max (1/min), r = 0.87, p < 0.001. It also correlated well with exercise duration (r = 0.62, p < 0.001), suggesting that cardiac reserve is a major determinant of exercise capacity. In the study, cardiac reserve ranged from 0.27 to 5.65 W, indicating a 20-fold difference between the most impaired cardiac function and that of the fittest subject.CONCLUSIONS:
A non-invasive method of estimating physiological cardiac reserve was developed. The reserve was found to be a major determinant of exercise capacity in a population of normal subjects and patients with heart disease. This method may thus be used to provide a clearer definition of the extent of cardiac impairment in patients with heart failure.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Esportes
/
Tolerância ao Exercício
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Teste de Esforço
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Coração
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Insuficiência Cardíaca
Tipo de estudo:
Observational_studies
Limite:
Adolescent
/
Adult
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Aged
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Humans
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Middle aged
Idioma:
En
Ano de publicação:
1998
Tipo de documento:
Article