Primary objective is to evaluate the safety and performance of the implanted Subcutaneous implantable cardioverter defibrillator (S-ICD) system. A maximum of 10 subjects were to be enrolled and followed for one month to collect data on the safety, efficacy, and performance of the implanted S-ICD system. Additionally, patient comfort will be assessed as will cosmetic outcome.

Inclusion Criteria:

• replacement of an existing transvenous implantable cardioverter defibrillator (ICD) system
• American College of Cardiology/American Heart Association/Heart Rhythm Society (ACC/AHA/HRS) Class I or II indications for ICD implantation
• Age >= 18 years
• Appropriate pre-operative Electrocardiogram (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 ventricular tachyarrhythmias (VT) that is reliably terminated with anti-tachycardia pacing
• Patients with existing epicardial patches or subcutaneous electrodes in the left thoracic quadrant
• Patients with chronic renal failure, i.e. with a creatinine level of >2.5 mg/dl unless prescribed drug therapy known to increase creatinine levels in which case the value should be <= 3mg/dl

1 month