Comparing the Effects of Conivaptan and Diuretics on Plasma Neurohormones and Renal Blood Flow in Patients With Chronic Congestive Heart Failure

Conivaptan 20 mg IV bolus followed by a 4 hour infusion at 1.2 mg/hr

Furosemide will be given IV at the subjects usual oral dose up to 80 mg. If the dose is 80 mg or more only 1/2 the dose will be given IV.

Furosemide bolus first; conivaptan 20 mg IV bolus/infusion at 1.2 mg/hour for a total of 4 hours