Subcutaneous Implantable Defibrillator (S-ICD) System - CE Clinical Investigation

Inclusion Criteria: * Replacement of an existing implanted transvenous ICD system * Class I, Class IIa, or Class IIb ACC/AHA/HRS indications for patients without an existing transvenous ICD system * Age is \>= 18 years * Appropriate pre-operative ECG as measured with a specially developed template Exclusion Criteria: * Subjects unable or unwilling to provide informed consent * Any condition which precludes the subject's ability to comply with the study requirements * Females who are pregnant or lactating and pre-menopausal women who are unwilling to use adequate birth control for the duration of the study * Participation in another investigational device trial at any time during the conduct of the S-ICD system trial without written consent from the sponsor. * Patients with a serious medical condition and life expectancy of less than one year. * Patients with documented spontaneous and frequently recurring VT that is reliably terminated with anti-tachycardia pacing * Patients with existing epicardial patches or subcutaneous electrodes in the left thoracic quadrant * Patients with impaired kidney function as measured by a Cockcroft-Gault Glomerular Filtration Rate (GFR) with a GFR \<= 29.