INTRINSIC RV - Inhibition of Unnecessary RV Pacing With AV Search Hysteresis in ICDs

Inclusion Criteria: * Patients who meet VITALITY™AVT® ICD indications * Patients who sign and date a Patient Informed Consent prior to device implant * Patients who remain in the clinical care of the enrolling physician Exclusion Criteria: * Patients with current indication for CRT-D * Patients who previously had a pacemaker, ICD or CRT-D * Patients with chronic AF * Patients whose life expectancy is \<12 months due to other medical conditions * Patients who are expected to receive a heart transplant during the duration of the study * Patients with epicardial pacing leads * Patients who have CABG, PCI, cardiac or other arrhythmia surgery planned but not yet performed * Patients with or who are likely to receive a tricuspid or other valve prosthesis * Patients who are currently enrolled in another investigational study that would directly impact the treatment or outcome of the current study * Patients who are younger than 18 years of age * Patients who are pregnant * Patients who are mentally incompetent and cannot give Patient Informed Consent or participate in the study