 5. Patients undergoing treatment for CHF with standard CHF therapy, such as diuretic, digoxin and ACE inhibitors. All patients should be receiving ACE inhibitors prior to enrollment in this study unless contraindicated or intolerant. If intolerance has been established, the patient must have been withdrawn from these drugs for at least one month prior to randomization. Other medications such as hydralazine, nitrates or amiodarone may also be used. Therapy with amiodarone should not have started or stopped within 2 months of randomization. 