Assessment of Primary Prevention Patients Receiving An ICD - Systematic Evaluation of ATP

Inclusion Criteria: * Subject with a Boston Scientific transvenous ICD (de novo implant or upgrade from pacemaker to ICD) implanted because of one of the following: * Prior myocardial infarction (MI) and left ventricular ejection fraction (LVEF) ≤ 30% OR * Ischemic or non-ischemic cardiomyopathy, and LVEF ≤ 35%, and a New York Heart Association (NYHA) class II or III * Subject is age 21 or above, or is considered of legal age per given geography * Subject is willing and capable of providing informed consent * Subject is willing and capable of complying with follow-up visits as defined by this protocol Exclusion Criteria: * History of spontaneous sustained Ventricular Tachycardia (VT) (≥ 160 bpm at ≥ 30 seconds in duration) or Ventricular Fibrillation (VF) not due to a reversible cause * NYHA Class IV documented in the medical records within 90 calendar days prior to enrollment * Subject is eligible and scheduled for cardiac resynchronization (CRT) implant * Subjects with a previous subcutaneous ICD (S-ICD) * Subject with existing transvenous ICD (TV-ICD) device implanted for greater than 60 days * Subjects with coronary artery bypass graft surgery or percutaneous coronary intervention within the past 90 calendar days prior to enrollment * Subjects with documented myocardial infarction within the past 90 calendar days prior to enrollment * Subjects on the active heart transplant list * Subject who has a ventricular assist device (VAD) or is to receive a VAD * Life expectancy shorter than 18 months due to any medical condition (e.g., cancer, uremia, liver failure, etc…) * Subjects currently requiring hemodialysis * Subject who is known to pregnant or plans to become pregnant over the course of the trial * Subject is enrolled in any other concurrent clinical study, with the exception of local mandatory governmental registries and observational studies/registries, without the written approval from Boston Scientific