Efficacy and Safety of Leadless Pacemakers Versus Left Bundle Area Pacing - A Preliminary Exploration

Inclusion Criteria: 1. Age \> 18 2. Planned for: 1. permanent pacemaker implantation for AV node disease (first, second or third degree), OR 2. post-TAVR patient requiring permanent pacemaker implantation 3. Preserved ejection fraction \> 50% 4. Preserved sinus node function 5. Willingness to adhere to study restrictions and comply with all post-procedural follow-up requirements 6. Life expectancy \> 1 year 7. Female subject of childbearing potential is not pregnant, not breast feeding, does not plan to be pregnant during the course of the study, and agrees to use a highly effective contraceptive method (i.e. IUD, birth control, vasectomized partner, sexual abstinence, etc.) during the course of the study. 8. Subject has been informed of the nature of the study, agrees to its provision and has provided written informed consent, approved by the IRB Exclusion Criteria: 1. Sinus node dysfunction, anticipating atrial pacing or persistent atrial fibrillation 2. Anatomical restriction for either MICRA or transvenous pacing such as 1. Access vein occlusion or thrombosis 2. previous radiation therapy at insertion site 3. inferior vena cava filter 3. Endstage renal disease (ESRD)/on dialysis 4. Dementia (inability to give consent) 5. Moderate to Severe or Severe Tricuspid valve regurgitation 6. Moderate to Severe or Severe Mitral valve regurgitation 7. History of mitral or tricuspid valve surgery 8. Preexisting implanted pacemaker or ICD or lead 9. Subject is allergic to titanium 10. Life expectancy \< 1 year 11. Recurrent or high risk of infections 12. Active malignancy requiring systemic chemotherapy or local chest radiation 13. Subject has myocardial infarction, unstable angina, cerebrovascular accident, or heart failure admission within 3 months of the baseline visit 14. CABG, valve surgery or PCI within the last 3 months except TAVR 15. Other major cardiac surgery within the last 6 months 16. Persistent and permanent atrial fibrillation diagnosed by a healthcare provider 17. NYHA class 3 or 4 Heart Failure Additional post-TAVR Exclusion Criteria: 18. Evidence of renal injury (12 hours post-TAVR) 19. Access site complication(s) post-TAVR 20. Suspicion of stroke/cerebrovascular accident (CVA) or transient ischemic attack (TIA) within 12 hours post-TAVR 21. Physician suspicion that ambulation to pre-TAVR activities post-pacemaker implantation would be unattainable 22. Other post-TAVR complications that in the opinion of the investigator may seriously confound study outcomes