The purpose of the study is two-fold. In Phase I (Protecta Clinical Study), system performance will be evaluated. In Phase II (PainFree SST), the inappropriate shock-free rate at one year of subjects implanted with a Medtronic Protecta implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy defibrillator (CRT-D) will be evaluated.

The PainFree SST study was a prospective, multicenter clinical trial, which was conducted in two consecutive phases. Phase I assessed safety as determined by assessment of delays in ventricular fibrillation (VF) arrhythmia detection time using new algorithms. Phase II assessed the influence of new algorithms on inappropriate and unnecessary shocks at 1 year of follow-up. Subjects enrolled in Phase I continued in Phase II of the study and data from all enrolled subjects contributed to the analysis of Phase II objectives. A sub-study of Phase II randomized secondary prevention subjects to either 18/24 NID or 30/40 NID in order to assess the safety of prolonged detection in these patients.

Inclusion Criteria:

• Patients meeting one of the following criteria can be included in Phase I of the study:

  • Patients indicated (per local indications) for a dual chamber implantable cardioverter defibrillator (DR-ICD)/cardiac resynchronization therapy defibrillator (CRT-D)
  • Patients undergoing a device replacement or upgrade to DR-ICD or CRT-D and with the protocol required leads (patients must be enrolled prior to implant)

• Patients meeting one of the following criteria can be included in Phase II of the study:

  • Patients indicated for a DR-ICD/VR-ICD/CRT-D device and intended to receive a Protecta device
  • Patients undergoing a DR-ICD/VR-ICD/CRT-D device replacement or an upgrade to a Protecta DR-ICD/VR-ICD or CRT-D
  • Patients indicated for a DR-ICD/VR-ICD/CRT-D already implanted with a Protecta device and the protocol required leads, who have not yet been discharged after implant

Exclusion Criteria:

• Patients with a mechanical tricuspid heart valve
• Patients enrolled or intended to participate in any concurrent drug and/or device study, which would confound the results of this trial as determined by Medtronic, during the course of this clinical study
• Patients with medical conditions that preclude the testing required for all patients by the study protocol or that otherwise limit study participation required for all patients
• Patients with exclusion criteria required by local law (e.g. age, pregnancy, breast feeding, etc)
• Patients anticipated not being able to complete the study
• Patients unwilling to provide written informed consent