Effect of G-suit protection on carotid-cardiac baroreflex function.
Aviat Space Environ Med
; 71(1): 31-6, 2000 Jan.
Article
en En
| MEDLINE
| ID: mdl-10632128
ABSTRACT
INTRODUCTION:
To test the hypothesis that G-suit inflation could increase cardiac chronotropic responses to baroreceptor stimulation and enhance baroreflex buffering of BP, the carotid-cardiac baroreflex response of 12 subjects was measured across two levels of lower body negative pressure (LBNP = 0 and 50 mm Hg) and two levels of G-suit inflation (0 and 50 mm Hg) in random order.METHODS:
Carotid-cardiac baroreflex stimulation was delivered via a silastic neck pressure cuff and responsiveness quantified by determination of the maximum slope of the stimulus-response function between R-R intervals (ms) and their respective carotid distending pressures (mmHg).RESULTS:
Mean +/- SE baseline control baroreflex responsiveness was 3.8+/-0.4 ms x mm Hg(-1). LBNP reduced the baroreflex response to 2.7+/-0.4 ms x mm Hg(-1), but G-suit inflation with LBNP restored the baroreflex response to 4.3+/-0.6 ms x mm Hg(-1).CONCLUSIONS:
These results suggest that, in addition to increased venous return and elevated peripheral resistance, G-suit inflation may provide protection against the debilitating effects of blood distribution to the lower extremities during orthostatic challenges such as standing or high +Gz acceleration by increasing cardiovascular responsiveness to carotid baroreceptor stimulation.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Presorreceptores
/
Arterias Carótidas
/
Trajes Gravitatorios
/
Frecuencia Cardíaca
Tipo de estudio:
Clinical_trials
Límite:
Adult
/
Humans
/
Male
Idioma:
En
Revista:
Aviat Space Environ Med
Año:
2000
Tipo del documento:
Article
País de afiliación:
Estados Unidos