Sufficient enrollments under current protocol for further development & studies

The proposed study is designed to characterize defibrillation efficacy in humans for the potential development of a new extravascular implantable cardioverter defibrillator (ICD) system.

The study recruited male and female subjects that met all of the inclusion criteria and none of the exclusion criteria. All subjects were scheduled to undergo surgical procedures outlined in the inclusion criteria. These surgical procedures were chosen as the patient population for this study because these procedures require similar personnel and may require access to similar or the same spaces as the ASD procedure.

The entire ASD study research system was removed prior to proceeding with the subject's planned surgery per standard medical practice, which then proceeded according to the standard of care.

Subjects were followed through their routine post-surgery follow-up visit.

At the time of completing the follow-up visit, the subjects' participation was complete and the subjects exited the study.

Inclusion Criteria:

• Subject must be undergoing surgical procedure for approved indications for
• cardiothoracic surgery where a midline sternotomy is planned, or
• implant of a transvenous (TV) ICD or subcutaneous ICD (S-ICD®), or
• VT ablation procedure, or
• VT inducibility testing during Electrophysiology (EP) study
• Subject must be willing to provide Informed Consent
• Subject must be ≥ 18 years old

Exclusion Criteria:

• Subject is considered to be at high risk for infection
• Subject has Left Ventricular Ejection Fraction (LVEF) ≤ 20%
• Subject at high risk of stroke
• Subject with an implanted active cardiac or non-cardiac device during study procedure (e.g., ICD, S-ICD®, Pacemaker, Neuro stimulator)
• Subject is pacemaker dependent
• Subject had previous pericarditis or prior sternotomy
• Subject has hiatus hernia or moderate or worse pectus excavatum
• Subject has hypertrophic cardiomyopathy
• Subject has severe aortic stenosis
• Subject has severe proximal three vessel coronary disease (over 70% in each vessel)
• Subject has >50% left main stem (LMS) disease
• Subject has known skin irritations to the Physio Control Fast Patch ECG Electrode
• Subject is enrolled in a concurrent study that may confound the results of this study, without documented pre-approval from a Medtronic study manager
• Subject has medical conditions that would limit study participation
• Subject is pregnant
• Subject meets exclusion criteria required by local law (e.g. age, breast feeding, etc.)

Baseline Assessment to routine Post-surgery follow-up visit.