The activity of the sympathetic nervous system as reflected both by plasma norepinephrine (NE) and direct neural recordings is increased in patients with congestive heart failure (CHF).1-3 The mechanisms by which stimulation of the sympathetic nervous system is initiated and maintained are not well characterized. The response of the sympathetic nervous system to further stimulation in CHF is often blunted.4-6 No information is currently available concerning ganglionic or preganglionic regulation of sympathetic activity in this disease. It is conceivable that hyperresponsiveness to central or ganglionic stimuli could play a role in the chronically elevated sympathetic tone in heart failure. Alternatively, subnormal responsiveness to such stimuli could help explain the blunted response to further sympathetic stimulation. We performed the current study to investigate whether the sympathetic response to ganglionic stimulation was normal, enhanced or depressed in patients with chronic CHF.