Aortic input impedance in infants and children.
J Appl Physiol (1985)
; 88(6): 2227-39, 2000 Jun.
Article
en En
| MEDLINE
| ID: mdl-10846040
ABSTRACT
Flow and pressure measurements were performed in the ascending aortas of six pediatric patients ranging in age from 1 to 4 yr and in weight from 7.2 to 16.4 kg. From these measurements, input impedance was calculated. It was found that total vascular resistance decreased with increasing patient weight and was approximately one to three times higher than those of adults. Conductance per unit weight was relatively constant but was approximately three times higher than for adults. Strong inertial character was observed in the impedance of four of the six patients. Among a three-element and two four-element lumped-parameter models, the model with characteristic aortic resistor (R(c)) and inertance in series followed by parallel peripheral resistor (R(p)) and compliance fitted the data best. R(p) decreased with increasing patient weight and was one to three times higher than in adults, and R(c) decreased with increasing patient weight and was 2 to 15 times higher. The R(p)-to-R(c) ratio differed significantly between infants and children vs. adults. The results suggested that R(p) developed more rapidly with patient weight than did R(c). Compliance values increased with increasing patient weight and were 3 to 16 times lower than adult values.
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Base de datos:
MEDLINE
Asunto principal:
Aorta
/
Resistencia Vascular
Tipo de estudio:
Prognostic_studies
Límite:
Child, preschool
/
Humans
/
Infant
Idioma:
En
Revista:
J Appl Physiol (1985)
Asunto de la revista:
FISIOLOGIA
Año:
2000
Tipo del documento:
Article
País de afiliación:
Estados Unidos