A computer study of the relation between chamber mechanical properties and mean pressure-mean flow of the left ventricle.
Circ Res
; 62(6): 1121-33, 1988 Jun.
Article
en En
| MEDLINE
| ID: mdl-3383361
Computer simulation of left ventricular contraction was used to analyze the mean left ventricular pressure-mean flow relation with changes of parameter values: end-diastolic volume, contractile state, internal resistance, characteristic resistance, capacitance, end-diastolic stiffness, and heart rate and with changes of experimental conditions: filling kinetics (constant atrial pressure as opposed to constant end-diastolic volume) and coronary perfusion pressure (constant or varying with atrial pressure, i.e., self-perfused). The chamber mechanical properties used in the simulation were defined in terms of a modified purely elastic behavior model with a flow-dependent resistive component. Computed results showed that at constant end-diastolic volume and constant ventricular perfusion pressure the mean pressure-mean flow relation was linear, except for changes in internal resistance where a cubic fit of points was more appropriate. In these conditions, parameter variations in the accepted linear relation produced changes in the slope and mean pressure axis intercept. Imposition of changes in experimental conditions gave rise to nonlinear mean pressure-mean flow relations. The results indicate that with elastic-resistive chamber mechanical properties as a starting point, the experimental conditions would be responsible for the different shapes of the mean pressure-mean flow relation obtained in isolated heart experiments. However, a more complete description of chamber properties (such as the addition of a deactivation component) could also give rise to nonlinear pump function graphs.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Presión Sanguínea
/
Circulación Coronaria
/
Modelos Cardiovasculares
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Circ Res
Año:
1988
Tipo del documento:
Article
País de afiliación:
Argentina
Pais de publicación:
Estados Unidos