What question did this study set out to answer?

To evaluate the effects of sympathetic baroreflex activation on right ventricular and right coronary hemodynamics under constant-pressure coronary perfusion.

August 1, 1981AJP Heart and Circulatory Physiology

Carotid sinus reflex vasoconstriction in right coronary circulation of dog and pig

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Why the study?

Does carotid occlusion alter right ventricular and right coronary hemodynamics in anesthetized vagotomized dogs and pigs?

Population

Anesthetized vagotomized dogs and pigs

Comparison

Carotid occlusion vs Baseline/control state

Design

Preclinical

Authors

SEStephen ElyNova Southeastern University DSDonald C. SawyerQuinnipiac University DADuncan AndersonHammersmith Hospital

Discussion

Member takes

Implication

Should not inform clinical decisions; extends preclinical evidence for alpha-adrenergic dominance in right coronary responses to baroreflex activation.

Key Points

To evaluate the effects of sympathetic baroreflex activation on right ventricular and right coronary hemodynamics under constant-pressure coronary perfusion.
Assessed anesthetized, vagotomized dogs and pigs undergoing carotid occlusion during constant-pressure coronary perfusion.
Tested right coronary vascular responses before and after pharmacological autonomic blockade using propranolol (beta-blocker) and phentolamine (alpha-blocker).
Measured right ventricular hemodynamics, coronary vascular resistance, and myocardial oxygen consumption.
Carotid occlusion in dogs increased heart rate, aortic pressure, and right ventricular dP/dt, while inducing a sustained 13% decrease in right coronary blood flow and a 14% increase in coronary vascular resistance.
Right coronary vasoconstriction was unaffected by beta-blockade with propranolol but was abolished by alpha-blockade with phentolamine.
Right ventricular oxygen consumption in pigs was low at baseline (4.8 ± 0.4 ml O2·min⁻¹·100 g⁻¹) and rose only slightly during carotid occlusion (5.15 ± 0.8 ml·min⁻¹·100 g⁻¹).

Structured PICO

Does carotid occlusion alter right ventricular and right coronary hemodynamics in anesthetized vagotomized dogs and pigs?

Population

Anesthetized vagotomized dogs and pigs

Intervention

Carotid occlusion (with and without beta-blockade with propranolol or alpha-blockade with phentolamine)

Comparator

Baseline/control state

Outcome

Right ventricular and right coronary hemodynamics (heart rate, aortic pressure, right ventricular dP/dt, right coronary artery blood flow, coronary vascular resistance, O2 consumption)surrogate

Baroreflex-mediated sympathetic stimulation evokes minor metabolic activity increases in the right ventricular myocardium, allowing direct neural alpha-vasoconstrictor effects to predominate.

Cite This Study

Ely et al. (1981) studied this question.

synapsesocial.com/papers/6a6f23ff8031ec7bb1db9d13 https://doi.org/10.1152/ajpheart.1981.241.2.h149

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Implication

Should not inform clinical decisions; extends preclinical evidence for alpha-adrenergic dominance in right coronary responses to baroreflex activation.

Carotid sinus reflex vasoconstriction in right coronary circulation of dog and pig

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Carotid sinus reflex vasoconstriction in right coronary circulation of dog and pig

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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