This is a Phase I/IIa Dose-Escalation, First exposure in Humans, Study Evaluating the Safety and Tolerability of CXL-1020 and Specific Effects on Electrocardiographic and Non-Invasive Hemodynamic Parameters in Patients with Chronic Heart Failure. 4 weekly four-hour treatments involving ascending dosages of CXL-1020 with a randomly interspersed placebo dose within two or more unique patient cohorts. Separate echocardiography cohorts (Echo Cohort A and Echo Cohort B) will evaluate a sustained dose over 4 hours (ECHO A), and an ascending two dose level, 4-hour infusion (2 hours each) (ECHO B), in individual patients. Echo Cohort dosages will be determined from responses observed in previous cohort exposures.