Key result
Intracoronary phenylephrine exerted a positive inotropic effect that was significantly attenuated in patients with ventricular failure (108 ± 28 mm Hg/sec) vs normal subjects (248 ± 54 mm Hg/sec; p<0.03).
Why the study?
Does stimulation or blockade of myocardial alpha-1-adrenergic receptors affect left ventricular contractility in humans with normal or failing hearts?
Population
15 patients with angiographically normal coronary arteries
Comparison
Intracoronary infusion of phentolamine and… vs Phentolamine alone and comparison between…
Design
Other
Follow-up
Acute (during infusion)
Authors
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Blunted alpha-1 inotropy in ventricular failure may limit agonist utility; leaves open blockade effects on basal contractility.
Does stimulation or blockade of myocardial alpha-1-adrenergic receptors affect left ventricular contractility in humans with normal or failing hearts?
Absolute Event Rate: 108% vs 248%
p-value: p=<0.03
Myocardial alpha-adrenergic stimulation exerts a positive inotropic effect that is attenuated in heart failure, but these receptors do not maintain basal contractility.
Landzberg et al. (1991) studied Left ventricular failure (n=15). Intracoronary phentolamine and phenylephrine vs. Normal left ventricular function was evaluated on Change in contractile state assessed by left ventricular peak (+)dP/dt (p=<0.03). Intracoronary phenylephrine exerted a positive inotropic effect that was significantly attenuated in patients with ventricular failure (108 ± 28 mm Hg/sec) vs normal subjects (248 ± 54 mm Hg/sec; p<0.03).
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