Synchronized Diaphragmatic Stimulation in Symptomatic Heart Failure

Inclusion Criteria: * NYHA classes II/III on optimal Guideline Directed Medical Therapy (GDMT) for 3 months * EF≤ 40% * At the time of consent, willing and able to comply with protocol requirements, including attending all required visits * Willing to participate in the study and able to sign an informed consent form * ≥18 years of age at the time of consent Exclusion Criteria: * Baseline 6-minute walk test \> 500 meters or \< 200 meters * NT-proBNP\< 250 if on loop diuretics, or NT-proBNP \< 500 if not on loop diuretics * Supine resting heart rate \> 140 bpm * Systolic blood pressure \< 80 mmHg or \> 170 mmHg * Serum creatinine \> 2.5 mg/dL * Serum hepatic function 3x ULN * Any of the following within the previous 3 months: unstable angina, AMI, CABG, PTCA, CVA/TIA, AF (episodes \> 24 hours), symptomatic NSVT or DCCV * Any inotropic drug treatment within the previous 3 months * Bradycardia (heart rate \< 50 beats/min), atrial arrhythmias with rates \> 100 beats/min, sustained ventricular tachycardia or frequent ventricular ectopy \>10% present during screening * Significant uncontrolled symptomatic bradyarrhythmia, atrial fibrillation, unstable ventricular arrhythmias or frequent ventricular ectopy \> 10% documented within the previous 3 months * Reversible non-ischemic cardiomyopathy * Valvular disease requiring intervention within the next 12 months or presence of significant valve disease as determined by the site cardiologist as: 1. Greater than mild mitral valve stenosis 2. Greater than moderate mitral valve regurgitation 3. Greater than mild tricuspid valve stenosis 4. Greater than moderate-severe tricuspid valve regurgitation 5. Greater than moderate aortic stenosis 6. Greater than moderate aortic regurgitation 7. Greater than mild-moderate pulmonic stenosis 8. Greater than moderate pulmonic regurgitation * Severe primary pulmonary disease, including pulmonary arterial hypertension. PAP sys \>70 mmHg at rest * Severe COPD, other respiratory or lung diseases where FEV1 \< 50% * Presence of more than small pleural effusion or history of pleural drainage within the previous 6 months * Known history of diaphragmatic paralysis or suspicion confirmed by unilateral or bilateral elevation of the diaphragm on chest x-ray * Pericardial disease * Non-cardiac condition substantially impairing ambulation of 6-minute hall walk test interpretation * Existing diaphragmatic stimulation for respiration assist * Present LVAD, Baroreflex Activation Therapy, Cardiac Contractility Modulation or interatrial shunt devices; temporary mechanical cardiac assist devices (current or within the previous 3 months) * Contraindications to laparoscopic access to the diaphragm, as determined by the implanting physician * Known intra-abdominal pathology which could increase the risk of laparoscopic access to the diaphragm. * Previous open laparotomy within 1 year * Previous thoracic or abdominal organ transplant * Drug induced immuno-suppression * Body mass index \> 40 * Enrollment in a concurrent investigation / clinical study * Having a life expectancy of \<1 year due to any condition * Pregnant or planning a pregnancy during the study period * Known allergies to implantable device materials * History of systemic infection requiring the use of intravenous antibiotics within the previous 3 months * Received cardiac resynchronization therapy (CRT) within six months of randomization, or is actively receiving CRT * Currently have a Class I indication for a cardiac resynchronization therapy (CRT) device according to AHA/ACC/ESC guidelines for the treatment of congestive heart failure