Inclusion Criteria

• Must be undergoing surgical procedure for approved indications for
  • Cardiothoracic surgery where a midline sternotomy is planned
  • Cardiothoracic surgery where a subxiphoid/paraxiphoid cut for a chest tube is planned
  • VT ablation procedure with epicardial access
  • Implant of a subcutaneous ICD (S-ICD®)
  • Implant of a transvenous ICD (single or dual chamber)
• Must be willing to provide informed consent
• Must be ≥ 18 years old

Exclusion Criteria

• Has known hiatus hernia, or moderate or worse pectus excavatum
• Had previous pericarditis or prior sternotomy
• Has known significant Right Ventricle/ Right Ventricular dilation
• Has hypertrophic cardiomyopathy
• Is pacemaker dependent
• Has known skin irritations due to the Covidien Multi-function defibrillation electrode
• Is considered to be at high risk for infection
• Has Left Ventricular Ejection Fraction < 20% (most recent available LVEF measurement in the last 6 months)
• Has New York Heart Association Class IV
• Has myocardial infarction within the last 6 weeks
• Currently has unstable angina
• Has severe aortic stenosis
• Is at high risk of stroke
• Has chronic obstructive pulmonary disease and is oxygen dependent
• Has permanent AF and will not be adequately anticoagulated during the ASD2 Acute Testing procedure
• Has an implanted active cardiac or non-cardiac device during the ASD2 acute testing procedure (e.g., ICD, S-ICD®, Pacemaker, Neuro stimulator)
• Is enrolled in a concurrent study that may confound the results of this study, without documented pre-approval from a Medtronic study manager
• Has any medical condition that would limit study participation
• Is pregnant, or of childbearing potential and not on a reliable form of birth control
• Women of childbearing potential are required to have a negative pregnancy test within 7 days prior to the ASD2 acute testing procedure
• Meets exclusion criteria required by local law (e.g. age, breast feeding,etc.)
• Is legally incompetent
  • If at high risk for infection, decision will be based on the local investigator judgment decision
  • If at high risk for stroke should be screened according to local country guidelines or, in case of their absence, according to ACC/AHA/ESC 2006 Guidelines for High Risk Factors for Stroke (i.e. exclusion of subjects with previous stroke, TIA, or embolism; Mitral stenosis; prosthetic heart valve).
  • Screening will be based on the local investigator judgment decision