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Human internal thoracic artery reactivity to dopaminergic agents
1Division of Cardiovascular Surgery, Victoria Hospital, University of Western Ontario, London, Canada.
Circulation
|November 1, 1993
Summary
Dobutamine and dopexamine cause vasodilation in the internal thoracic artery (ITA), unlike dopamine which may worsen vasoconstriction. This impacts drug choices in coronary bypass surgery (CBS).
Area of Science:
- Cardiovascular Pharmacology
- Vascular Biology
- Surgical Research
Background:
- Internal thoracic artery (ITA) vasospasm is a common clinical issue.
- Dopaminergic agents are frequently used in patients undergoing coronary bypass surgery (CBS).
Purpose of the Study:
- To characterize the vascular reactivity of human ITA to key dopaminergic agents.
- To assess the potential for vasodilation or vasoconstriction induced by dopamine, dobutamine, and dopexamine in the ITA.
Main Methods:
- Human ITA segments from CBS patients were used in tissue bath studies.
- Vascular responses (relaxation and constriction) to phenylephrine, acetylcholine, dopamine, dobutamine, and dopexamine were measured.
- Endothelial function was assessed using acetylcholine-induced relaxation.
Main Results:
- Dobutamine and dopexamine induced significant vasodilation in ITA segments.
- Dopamine did not cause vasodilation and showed vasoconstriction at high concentrations.
- Endothelial function did not significantly alter the ITA's response to these dopaminergic agents.
Conclusions:
- Dobutamine and dopexamine demonstrate vasodilatory properties in the human ITA.
- High-dose dopamine may exacerbate ITA vasoconstriction, posing a potential risk.
- These findings have implications for managing vascular tone during and after CBS.