Sympathoinhibitory response to clonidine is blunted in patients with heart failure.

Lang CC, Stein CM, Nelson RA, He HB, Belas FJ, Blair IA, Wood M, Wood AJ
Hypertension. 1997 30 (3 Pt 1): 392-7

PMID: 9314422 · DOI:10.1161/01.hyp.30.3.392

To determine whether alpha2-adrenergic-mediated sympathoinhibition was altered in chronic heart failure, sympathoinhibitory sensitivity was assessed using the alpha2-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 microg/min) than in control subjects (0.7+/-0.1 microg/min, P=.05). Compared with control subjects, the decrement in norepinephrine spillover to cumulative doses of clonidine (1, 2, and 3 microg/kg administered intravenously) was significantly less in patients with heart failure (P<.05). Blood pressure also tended to decrease less in patients with heart failure (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<.01 and 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.

MeSH Terms (12)

Adrenergic alpha-Agonists Aged Clonidine Heart Failure Hemodynamics Humans Kinetics Neural Inhibition Norepinephrine Osmolar Concentration Reference Values Sympathetic Nervous System

Connections (1)

This publication is referenced by other Labnodes entities:

Links