Cardiac output response to exercise in chronic cardiac failure patients.
Int Heart J
; 53(5): 293-8, 2012.
Article
em En
| MEDLINE
| ID: mdl-23038090
ABSTRACT
The purpose of this study was to investigate the precise pattern of stroke volume (SV) response during exercise in patients with chronic heart failure (CHF) compared with age-matched controls. Fourteen patients with CHF and 7 controls performed symptom-limited bicycle exercise testing with respiratory gas exchange measurement. Patients were classified into group A (n = 7) with peak VO2 ≥ 18.0 mL/kg/minute and group B (n = 7) with peak VO2 < 18.0 mL/kg/ minute. SV and cardiac output (CO) were continuously measured during exercise using a novel thoracic impedance method (Physioflow). CO and SV were lower in the group B patients than those in controls at peak exercise [CO 11.3 ± 1.0 (SE) versus 15.6 ± 0.9 L/minute, P < 0.05, SV 89 ± 6 versus 110 ± 6 mL, P < 0.05]. SV reached its peak levels during submaximal exercise and remained close to the peak value until peak exercise in 6 of 7 group B patients (86%). On the other hand, it progressively increased until peak exercise in 6 of 7 controls (86%) and 5 of 7 group A patients (71%). In all subjects, CO at peak exercise was more closely correlated with SV at peak exercise (r = 0.86, P < 0.001) than with peak heart rate (r = 0.69, P < 0.001). CHF patients with impaired exercise capacity had attenuated increment of CO during exercise, and SV reached its peak levels during submaximal exercise.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Débito Cardíaco
/
Exercício Físico
/
Insuficiência Cardíaca
Tipo de estudo:
Observational_studies
Limite:
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Int Heart J
Ano de publicação:
2012
Tipo de documento:
Article