Sympathoinhibitory response to clonidine is blunted in patients with heart failure
| Autor: | Ian A. Blair, Chim C. Lang, Alastair J. J. Wood, Margaret Wood, Huai B. He, C. Michael Stein, Richard Nelson, Frank J. Belas |
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| Rok vydání: | 1997 |
| Předmět: |
Agonist
Sympathetic nervous system Sympathetic Nervous System Heart disease medicine.drug_class Hemodynamics Clonidine Norepinephrine (medication) Norepinephrine Reference Values Internal Medicine Medicine Humans Aged Heart Failure business.industry Osmolar Concentration Neural Inhibition medicine.disease Kinetics Blood pressure medicine.anatomical_structure Anesthesia Heart failure business Adrenergic alpha-Agonists medicine.drug |
| Zdroj: | Hypertension (Dallas, Tex. : 1979). 30(3 Pt 1) |
| ISSN: | 0194-911X |
| Popis: | Abstract To determine whether α 2 -adrenergic–mediated sympathoinhibition was altered in chronic heart failure, sympathoinhibitory sensitivity was assessed using the α 2 -adrenergic agonist clonidine in 7 patients with heart failure and in 10 healthy control subjects. Basal norepinephrine spillover was significantly higher in patients with heart failure (1.3±0.3 μg/min) than in control subjects (0.7±0.1 μg/min, P =.05). Compared with control subjects, the decrement in norepinephrine spillover to cumulative doses of clonidine (1, 2, and 3 μg/kg administered intravenously) was significantly less in patients with heart failure ( P P =.06). The doses of clonidine required to produce a 10% decrease in blood pressure and a 25% decrease in norepinephrine spillover were significantly higher in heart failure ( P P =.05, respectively). Thus, although clonidine lowers norepinephrine spillover significantly in patients with heart failure, such patients are less sensitive to clonidine than healthy control subjects. This difference in sensitivity suggests that doses of clonidine provide effective sympathoinhibition will need to be selected for studies that will evaluate the potential therapeutic effect of clonidine in heart failure. |
| Databáze: | OpenAIRE |
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