Cardiac Contractility Modulation (CCM) Therapy in Subjects With Medically Refractory Heart Failure

Inclusion Criteria: * Baseline ejection fraction ≥ 25% and ≤45% (as assessed by the site) * NYHA class II or III (chronic, not transient, heart failure) despite receiving optimal medical therapy for heart failure * Stable medication for heart failure for at least 30 days based on patient's medical records * Baseline Peak VO2 ≥ 10 and ≤ 18.5 ml O2/Kg/min (as assessed by the site) Exclusion Criteria: * Potentially correctible cause of HF (valvular, congenital, or untreated ischemic heart disease) * Clinically significant angina pectoris * Hospitalization for HF requiring the use of inotropic support or IV diuretics within 30 days of enrollment * PR interval greater than 375 ms * Permanent or persistent atrial fibrillation/flutter or cardioversion within 30 days of enrollment. * Exercise tolerance limited by condition other than heart failure (e.g., angina, chronic obstructive pulmonary disease (COPD), peripheral vascular disease, orthopedic or rheumatologic conditions) or unable to perform baseline stress testing * Scheduled for a coronary artery bypass graft (CABG) or a percutaneous transluminal coronary angioplasty (PTCA) procedure, or CABG procedure within 90 days or a PTCA procedure within 30 days of enrollment. * Biventricular pacing system, or indication for Biventricular pacing system * Myocardial infarction within 90 days of enrollment. * Mechanical tricuspid or aortic valves. * Ventricular assist device * Prior heart transplant * Pregnant or planning to become pregn…