The activity of the sympathetic nervous system seems to influence the uptake (and handling) of glucose by the skeletal muscle of the forearm. Conditions in which sympathetic activity is increased seem to inhibit/reduce forearm glucose uptake. Inversely a decrease in sympathetic activity seems to increase glucose uptake. This study analyzes the effect of alfa-adrenergic receptor blockade (counteracting sympathetic influence) on insulin-stimulated forearm glucose uptake in patients with increased sympathetic activity (patients with chronic heart failure).

Inclusion Criteria:

• Heart failure of at least New York Heart Association (NYHA) class II
• Left ventricular ejection fraction (LVEF) <= 40%
• Age 18-75 years

Exclusion Criteria:

• Alfa-blockers, or beta-blockers with alfa-blocking activity (carvedilol)
• Tricyclic antidepressants
• Warfarin derivatives (acetylic salicylic acid and clopidogrel are allowed)
• Hospitalisation in 6 weeks prior to the study
• Any change in medication in 6 weeks prior to the study
• Unstable angina
• Orthopnoea
• Known chronic disease of the autonomic nervous system
• Diabetes mellitus
• Oedema of the lower extremities, complicating the insertion of a venous catheter in a vein on the foot