Type I complications are adverse events caused by a component of the S-ICD System (i.e. pulse generator, electrode, EIT or programmer) that results in permanent loss of device function, invasive intervention or death.

S-ICD PAS enrolled de novo implant subjects as well as prior IDE participants. Primary Safety endpoint includes subjects enrolled in S-ICD PAS combined with the subjects from the S-ICD IDE (NCT# 01064076). S-ICD PAS had 1643 de novo implant attempts and 123 prior IDE implant subjects, for endpoint analyses this was combined with the data from the 198 IDE implant attempt subjects that did not participate in S-ICD PAS, totaling 1964 subjects.

Overall shock effectiveness refers to conversion of an episode following on any of the 5 shocks (maximum) that may be delivered during a single episode. Discrete episodes of VT/VF are those that are temporally independent (<3 within a 24 hour period), unlike storm episodes, which occur in clusters (≥3 episodes within a 24 hour period). Episodes that spontaneously terminate will be excluded from this endpoint since the effectiveness of the shock cannot be evaluated in such circumstances.

Primary effectiveness endpoint includes subjects in S-ICD PAS combined with the subjects from the S-ICD IDE (NCT# 01064076). S-ICD PAS had 1637 de novo implants and 123 prior IDE implant subjects, for endpoint analyses this was combined with the data from the 191 IDE implanted subjects that did not participate in S-ICD PAS, totaling 1951 subjects. This endpoint analyzes all appropriate shocks.

The electrode related complications analyzed for this end-point include: complications occurring less than or equal to 30 days post implant that are attributable to structural electrode failure for electrode movement, electrode impendence out of range, electrode conductor fracture, deformation or breakage or insulation failure; OR occurring greater than 30 days post implant regardless of structural failure for electrode movement, electrode impendence out of range, electrode conductor fracture, deformation/breakage or insulation failure; OR occurring greater than 30 days post implant attributable to structural electrode failure for incomplete/improper header connection, in-subject damage to electrode, electrode revision to optimize therapy, electrode movement, infection, oversensing/undersensing. Additionally, a complication is an adverse event that results in permanent loss of device function, invasive intervention or death.

Secondary safety endpoint includes subjects in S-ICD PAS combined with the subjects from the S-ICD IDE (NCT# 01064076). S-ICD PAS had 1643 de novo implant attempts and 123 prior IDE implant subjects, for endpoint analyses this was combined with the data from the 198 IDE implant attempt subjects that did not participate in S-ICD PAS, totaling 1964 subjects.

The rate in first shock effectiveness in converting induced (acute) and spontaneous discrete episodes of VT/VF through 60 months (1825 days) is calculated as the number of successful first shock conversions divided by the total evaluable episodes Acute Tests included: S-ICD PAS Study: Acute tests include induced episodes during the initial implant hospitalization after enrollment. Inductions may have been done on different days, but all occurred before the patient was discharged after initial implant; IDE Study : Acute tests included induced episodes occurring during the initial implant procedure as well as subsequent hospitalization until the final system position was obtained.

• Acute Test Shock Energy Levels included all energy levels in the PAS Study and only 65 Joule shocks in the IDE Study.
• Acute Test Arrhythmias included all VT and VF episodes for the PAS Study and only VF episodes for the IDE Study.

The secondary effectiveness endpoint includes subjects in S-ICD PAS combined with the subjects from the S-ICD IDE (NCT# 01064076). S-ICD PAS had 1637 de novo implants and 123 prior IDE implant subjects, for endpoint analyses this was combined with the data from the 191 IDE implanted subjects that did not participate in S-ICD PAS, totaling 1951 subjects. This endpoint analyzes all induced (acute) or spontaneous appropriately treated discrete VT/VF shocks.