What question did this study set out to answer?

This research aims to determine the individual contributions of carotid and aortic baroreceptors in the regulation of heart rate during varying arterial pressures.

December 1, 1985Journal of Clinical InvestigationOpen Access

Relative contribution of aortic and carotid baroreflexes to heart rate control in man during steady state and dynamic increases in arterial pressure.

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Why the study?

What is the relative contribution of carotid versus extracarotid (aortic) baroreflexes to heart rate control in normal humans during increases in arterial pressure?

Key Points

This research aims to determine the individual contributions of carotid and aortic baroreceptors in the regulation of heart rate during varying arterial pressures.
Conducted a trial with normal humans (n=10) using phenylephrine to increase mean arterial pressure.
Measured heart intervals and arterial pressure during steady-state and dynamic conditions.
Applied neck pressure to isolate the effects of aortic baroreceptors from carotid responses.
Phenylephrine infusion increased mean arterial pressure by 13 +/- 2 mmHg and prolonged heart interval by 230 +/- 24 ms (P<0.05).
Neck pressure application reduced heart interval response to 65 +/- 22 ms (P<0.05 vs. PE alone) and reduced prolongation by 41-70% in some subjects.
During dynamic increases in systolic arterial pressure, eliminating carotid baroreflex reduced heart interval response by 30% (baroreflex slope changed from 20.2 +/- 2.9 to 14.1 +/- 2.8 ms/mmHg, P<0.02).

Structured PICO

What is the relative contribution of carotid versus extracarotid (aortic) baroreflexes to heart rate control in normal humans during increases in arterial pressure?

Population

10 normal humans

Intervention

Phenylephrine (PE) infusion with superimposed neck pressure (NP) to counter transmural carotid sinus pressure increase (stimulating only aortic baroreceptors)

Comparator

Phenylephrine (PE) infusion alone (stimulating both carotid and aortic baroreceptors)

Outcome

Heart interval (HI) response and baroreflex slopesurrogate

Extracarotid (aortic) baroreflexes appear to have a greater role than carotid baroreflexes in controlling heart rate during dynamic increases in arterial pressure in humans.

Discussion

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Implication

Aortic baroreflexes predominate in HR control during pressure rises; leaves open translation to hypertension or device therapies.

Cite This Study

Ferguson et al. (1985) studied this question.

synapsesocial.com/papers/6a1eff90459b8c409ce6b79c https://doi.org/10.1172/jci112236

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Relative contribution of aortic and carotid baroreflexes to heart rate control in man during steady state and dynamic increases in arterial pressure.

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Relative contribution of aortic and carotid baroreflexes to heart rate control in man during steady state and dynamic increases in arterial pressure.

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Also Consider

Also Consider