- Subject is diagnosed with New York Heart Association (NYHA) class III or IV (within 30 days prior to enrollment) despite optimal medical therapy which is defined as: ACE-inhibitor (Angiotensin-Converting Enzyme) or Angiotensin II Receptor Blocker (ARB), if tolerated, for at least one month prior to implant, AND beta-blocker for at least three months preceding implant, if tolerated, and stable for one month, OR subject has an urgent medical need for an implantable cardioverter defibrillator (ICD) that precludes waiting the one or three months for the medication requirements for ACE inhibitor, ARB or beta-blocker