[Aging and efficiency of the baroreflex arc. Analysis of a large sample of normal individuals studied with a computerized technic].
Previous studies, with manifold contradictions, have shown the baroreflex progressive damage in the elderly. A group of 178 normal subjects, between 11 and 88 years age, were investigated by measuring their blood pressures and R-R intervals while at rest and during the Valsalva manoeuvre, deep breathing at 6 breaths/min, and standing up from a lying position. The parasympathetic parameters decreased with ageing; mean heart rate and its response during standing up diminished, suggesting a cardiac ortho-sympathetic alteration; and basal blood pressures increased, while its responses at the last manoeuvre did not change. All this indicates that cardiac parasympathetic activity is reduced and vascular ortho-sympathetic activity--C1 group--is increased. Probably, the cardiac ortho-sympathetic findings are originated by the receptors--because of the C1 neuronal hyperactivity. The destruction of inhibitory afferents with ageing could explain this hyperactivity.
Iglesias Guerrero
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M
Departmento de Medicina, Hospital General de Galicia, Facultad de Medicina, Universidad de Santiago de Compostela.
Araúxo Vilar
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D
Cabezas-Cerrato
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J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011311:Pressoreceptors / Q000502:physiology*; D012018:Reflex / Q000502:physiology*; D014636:Valsalva Maneuver / Q000502:physiology*
Envejecimiento y eficiencia del arco barorreflejo. Análisis de una amplia muestra de individuos normales estudiados con una técnica computadorizada.