Influence of cardiopulmonary receptors on the bradycardiac responses to carotid baroreceptor stimulation in man

G. Parati, G. Grassi, P. Coruzzi, L. Musiari, A. Ravogli, A. Novarini, G. Mancia

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Animal studies have shown that arterial baroreflexes are modulated by reflexes originating from the cardiopulmonary volume receptors, and that this modulation consists of a reduction of the inhibitory influence exerted by arterial baroreceptors on the heart and peripheral circulation. This has not been confirmed in man, however, in whom no reduction in the bradycardic response to carotid baroreceptor stimulation has been observed after the mild increase in central venous pressure (right atrial catheter) and cardiopulmonary receptor activity provided by passive leg raising. In seven normotensive subjects carotid baroreceptors were gradedly stimulated by progressively increasing carotid transmural pressure through a neck chamber device, the resulting reflex lengthening in R-R interval being measured in the two-three cardiac cycles immediately after the baroreceptor in control conditions and repeated during a head-out water immersion which increased central venous pressure (right atrial catheter) from 1.5 ± 0.2 to 12.0 ± 0.9 mmHg (mean ±SE), thereby providing a marked increase in the cardiopulmonary receptor stimulus. In the control condition graded stimulation of the baroreceptors caused a progressive lengthening in R-R interval, the maximal effect being +477.4 ± 57.2 ms. Immersion increased the R-R interval from 774.2 ± 3.2 to 961.56 ± 5.8 ms (P

Original languageEnglish
Pages (from-to)639-645
Number of pages7
JournalClinical Science
Issue number5
Publication statusPublished - 1987


ASJC Scopus subject areas

  • Medicine(all)

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