What does this research mean for the field?

Adjustments in cardiac output are not critically important for the buffering function of the carotid sinus baroreceptors in humans, as compensatory changes in systemic vascular resistance can adequately maintain arterial pressure. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

To determine the relative contributions of cardiac output and peripheral vascular resistance to the carotid sinus baroreflex in humans during directional pressure shifts and postural changes.

August 1, 1975Acta Physiologica Scandinavica

Cardiovascular Responses to Changes in Carotid Sinus Transmural Pressure in Man

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Why the study?

How do changes in carotid sinus transmural pressure affect systemic arterial pressure and cardiac output in healthy young men?

Population

8 physically well-trained young male volunteers

Comparison

Changes in carotid sinus transmural pressure in… vs Equal changes of carotid sinus transmural…

Design

Other

Authors

HBH. BjurstedtSwedish Defence University GRG. RosenhamerKarolinska Institutet GTGunnar TydénKarolinska University Hospital

Discussion

Member takes

Implication

Asymmetric baroreflex responses in healthy men support antihypotensive bias; leaves open translation to disease states.

Key Points

To determine the relative contributions of cardiac output and peripheral vascular resistance to the carotid sinus baroreflex in humans during directional pressure shifts and postural changes.
Assessed eight physically well-trained young male volunteers (N=8) in both supine and 70-degree head-up tilt positions.
Applied equal bidirectional shifts in carotid sinus transmural pressure before and during combined beta-adrenergic and parasympathetic autonomic blockade.
Decreased transmural pressure induced a stronger systemic arterial pressure response than increased transmural pressure, mediated by both elevated cardiac output and peripheral vasoconstriction.
Autonomic cardiac blockade eliminated the cardiac output rise associated with reduced transmural pressure without significantly impairing the overall arterial blood pressure response.
Head-up tilt during autonomic blockade exacerbated the decrease in cardiac output, but arterial pressure remained stable due to a compensatory increase in systemic vascular resistance.

Structured PICO

How do changes in carotid sinus transmural pressure affect systemic arterial pressure and cardiac output in healthy young men?

Population

8 physically well-trained young male volunteers

Intervention

Changes in carotid sinus transmural pressure (Ptm) (decrease and increase) in supine and 70 degrees head-up position, with and without combined beta-adrenergic and parasympathetic blockade

Comparator

Equal changes of carotid sinus transmural pressure in the opposite direction

Outcome

Systemic arterial pressure, vascular resistance, and cardiac outputsurrogate

This physiological study demonstrates that while cardiac output contributes to the pressor response to decreased carotid sinus transmural pressure, it is not critically important for the buffering function of carotid sinus baroreceptors in humans.

Cite This Study

Bjurstedt et al. (1975) studied this question.

synapsesocial.com/papers/6a1bd1f00a1f7575939cfe4c https://doi.org/10.1111/j.1748-1716.1975.tb05909.x

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Cardiovascular Responses to Changes in Carotid Sinus Transmural Pressure in Man

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Cardiovascular Responses to Changes in Carotid Sinus Transmural Pressure in Man

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider