Can a defibrillator lead thread through the Heart's middle cardiac vein?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Subject meets current clinical practice guidelines for implantation of ICD or CRT-D and will undergo one of the following: * Medtronic CRT-D system implant * Medtronic ICD system implant (single or dual chamber) 2. Anatomical suitability for middle cardiac vein lead placement based on pre procedural imaging. 3. Subject meets both of the following: * At least Moderate Tricuspid Valve Regurgitation documented by cardiac imaging * A clinical goal to avoid worsening tricuspid valve regurgitation as determined by the treating physician and/or the patient 4. Age 18 years or older. 5. Subject is willing to undergo implant defibrillation testing 6. Signed Patient Informed Consent Form (ICF). Exclusion Criteria: 1. Life expectancy \< 6 months due to non-cardiac comorbidities or advanced frailty where the procedure is not aligned with goals of care 2. Contraindication to transvenous lead implantation, including: * Severe or occlusive disease of the axillary/subclavian venous system * Coronary sinus or middle cardiac vein occlusion, severe stenosis, or anatomy prohibiting safe lead delivery * Known hypercoagulable state or bleeding disorder is not manageable with standard therapy. 3. Subject is contraindicated for ≤1 mg dexamethasone acetate 4. Patients with a medical condition that precludes them from undergoing defibrillation testing: * Pre-existing or suspected pneumothorax * Severe aortic stenosis * Current Intracardiac LA or LV thrombus * Severe proximal three-vessel or left main coronary artery disease without revascularization * Hemodynamic instability * Unstable angina * Recent stroke or transient ischemic attack (within the last 6 months) * Known inadequate external defibrillation * LVEDD \>70 mm * Any other known medical condition not listed that precludes their participation in the opinion of the Investigator. 5. Patient with evidence of active infection or undergoing treatment for an infection. 6. Inability to provide informed consent, including: * Cognitive impairment without a legally authorized representative * Language or communication barriers that prevent adequate understanding of the study 7. Unable to follow through study protocol for any reasons (social support, distance from research center, insurance denial, mental illness etc.) in the investigator's judgement 8. Pregnant women or breastfeeding women, or women of childbearing potential and who are not on a reliable form of birth regulation method or abstinence 9. End-Stage Renal Disease (ESRD) on dialysis 10. NYHA IV 11. Patient participation in another study that precludes concomitant study participation