Lead EvaluAtion for Defibrillation and Reliability (LEADR) / Lead Evaluation for Defibrillation and Reliability in Left Bundle Branch Area Pacing (LEADR LBBAP)

LEADR Inclusion Criteria: * Subject meets current clinical practice guidelines for implantation of ICD or CRT-D and will undergo one of the following: * de novo Medtronic CRT-D system implant * de novo Medtronic ICD system implant (single or dual chamber) * Subject has, per local law and requirements, the minimum age for autonomously signing an ICF (minimum age of 18 years) * Subject is willing to undergo implant defibrillation testing if requested. * Subject is geographically stable and willing and able to complete the study procedures and visits for the duration of the follow-up. LEADR Exclusion Criteria: * Subject is unwilling or unable to personally provide Informed Consent. * Subject has contraindications for standard RV transvenous lead placement (e.g., mechanical right heart valve). * Subject is contraindicated for ≤1 mg dexamethasone acetate. * Subject has a life expectancy of less than 12 months * For subject undergoing defibrillation testing the following medical conditions exclude them: * Pre-existing or suspected pneumothorax during implant * Current intracardiac left atrial or left ventricular (LV) thrombus * Severe aortic stenosis * Severe proximal three-vessel or left main coronary artery disease without revascularization * Unstable angina * Ejection Fraction less than 25% * Recent stroke or transient ischemic attack (within the last 6 months) * Known inadequate external defibrillation * Any other known medical condition not listed th…