Beat-to-beat stroke volume estimation from aortic pressure waveform in conscious rats: comparison of models.
Am J Physiol Heart Circ Physiol
; 281(3): H1148-55, 2001 Sep.
Article
em En
| MEDLINE
| ID: mdl-11514281
ABSTRACT
Several methods for estimating stroke volume (SV) were tested in conscious, freely moving rats in which ascending aortic pressure and cardiac flow were simultaneously (beat-to-beat) recorded. We compared two pulse-contour models to two new statistical models including eight parameters extracted from the pressure waveform in a multiple linear regression. Global as well as individual statistical models gave higher correlation coefficients between estimated and measured SV (model 1, r = 0.97; model 2, r = 0.96) than pulse-contour models (model 1, r = 0.83; model 2, r = 0.91). The latter models as well as statistical model 1 used the pulsatile systolic area and thus could be applied to only 47 +/- 17% of the cardiac beats. In contrast, statistical model 2 used the pressure-increase characteristics and was therefore established for all of the cardiac beats. The global statistical model 2 applied to data sets independent of those used to establish the model gave reliable SV estimates r = 0.54 +/- 0.07, a small bias between -8% to +10%, and a mean precision of 7%. This work demonstrated the limits of pulse-contour models to estimate SV in conscious, unrestrained rats. A multivariate statistical model using eight parameters easily extracted from the aortic waveform could be applied to all cardiac beats with good precision.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Aorta
/
Volume Sistólico
/
Vigília
/
Modelos Estatísticos
/
Modelos Cardiovasculares
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
Am J Physiol Heart Circ Physiol
Ano de publicação:
2001
Tipo de documento:
Article