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 that precludes their participation in the opinion of the investigator * Subject is enrolled or planning to enroll in a concurrent clinical study that may confound the results of this study, without documented pre-approval from a Medtronic study manager. * Subject with any exclusion criteria as required by local law (e.g., age or other). * Pregnant women or breastfeeding women, or women of childbearing potential and who are not on a reliable form of birth regulation method or abstinence * Subject with an existing pacemaker (including transcatheter pacing system), ICD, or CRT device or leads * Subject with any evidence of active infection or undergoing treatment for an infection * Recent (or planned) cardiac surgery or stenting less than 1 month before implant * End stage renal disease * Subjects with NYHA IV classification * Subjects with a transplanted heart * Subjects with previously extracted leads * Subjects with Left Ventricular Assist Device LEADR LBBAP Inclusion Criteria: * Subject meets current local clinical practice guidelines for implantation of ICD (single or dual chamber) or CRT-D system and will undergo one of the following: a) De novo Medtronic ICD system implant (single or dual chamber) or b) De novo Medtronic CRT-D system implant and is intended to also undergo LV lead implant (for patients indicated for CRT-D according to locally approved indications/indications) * Subject is 12 years of age or older and also is greater than 30 kg in weight at time of enrollment, has cardiac anatomy conducive to RV coil placement, and is allowed to participate in study per local law and requirements. Subjects from 12 years of age until adult also have a separate indication for pacing or CRT or are anticipated to develop one. * Subject provides written authorization and/or consent per institution and geographical requirements. * Subject is geographically stable and willing and able to complete the study procedures and visits for the duration of the follow-up * Subject is willing to undergo implant defibrillation testing if requested LEADR LBBAP Exclusion Criteria: * Subject has contraindication for screw-in active fixation 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 * Current intracardiac left atrial or LV thrombus * Severe aortic stenosis * Severe proximal three-vessel or left main coronary artery disease without revascularization * Unstable angina * Recent stroke or transient ischemic attack (within the last 6 months) * Known inadequate external defibrillation * Any other known medical condition not listed that precludes their participation in the opinion of the investigator * Subject is enrolled or planning to enroll in a concurrent clinical study that may confound the results of this study, without documented pre-approval from a Medtronic study manager * Subject is pregnant or breastfeeding, or subject is of childbearing potential and not on a reliable form of birth regulation method or abstinence * Subject with an existing pacemaker (including transvenous and transcatheter pacing system), ICD (transvenous) or CRT-D (transvenous) device or leads * Subject with previous subcutaneous ICD (S-ICD), extravascular ICD (EV ICD) or Implantable Cardiac Monitor explanted within 30 days before implant * Subject with any evidence of active bacterial infection or undergoing treatment for a bacterial infection within the last 30 days * Recent (or planned) cardiovascular intervention within 30 days before or after implant, such as cardiac surgery, cardiac ablation, Percutaneous Coronary Intervention (PCI), or temporary cardiac pacing for \>12 hours * Subjects with end stage renal disease * Subjects with NYHA IV classification * Subjects with a transplanted heart or on the waiting list for a heart transplant * Subjects with previously extracted leads * Subjects with Left Ventricular Assist Device * Subjects that are vulnerable adults