The purpose of the Long term Evaluation of Cardiac Arrhythmias after Transcatheter Aortic Valve Implantation (LOCATE) Registry is to perform long-term ambulatory monitoring of patients with severe aortic stenosis who undergo trans-catheter aortic valve implantation (TAVI) and develop new onset conduction system abnormalities post-procedure that do not require urgent permanent pacemaker (PPM) implantation. The primary objectives of this study are to assess the incidence of late onset heart block necessitating PPM implantation and to evaluate the incidence of new onset atrial fibrillation (AF) following TAVI. This study aims to provide valuable insights into the long-term cardiac health of TAVI patients and inform the development of improved treatment strategies for aortic stenosis patients with conduction system abnormalities.

Clinical management of the patients that develop conduction system abnormalities not severe enough to warrant a PPM implantation is uncertain due to limited prospective long-term data on outcomes in this patient population with significant variations in treatment approaches. While some electrophysiologists favor ambulatory monitoring with event monitors or Implantable loop recorder (ILR), small studies have shown a potential benefit of invasive electrophysiological studies for risk stratification. Most rhythm monitoring studies have only focused on arrhythmias in the first 2-4 weeks post implantation with very sparse data on longer term outcomes. In addition to conduction system abnormalities, other arrhythmias such as AF following TAVI have also been shown to be associated with worse long-term outcomes. However, prospective data on incidence and risk factors of post TAVI atrial fibrillation is limited.

This will be a prospective observational study (Registry). Patients that have undergone a TAVI procedure and meet inclusion and no exclusion criteria will be approached about participating in the study. Patients who have undergone Boston Scientific Loop Recorder (LUX-Dx Premarket Approval Application (PMA)# K193473) as standard of care for arrhythmia monitoring after TAVI will have the ILR monitored monthly by the electrophysiology team. All alerts will be reviewed and discussed with the implanting physician for further management. Patients will be followed for up to 12 months.

Inclusion Criteria:

• Patients > 18 years of age with severe aortic stenosis that undergo TAVI for severe aortic stenosis that develop any one of the following conduction system abnormalities on the immediate post procedural or post operative ECG and have undergone ILR implantation for long-term monitoring of these conditions:
• New left bundle branch block (QRS >120ms)
• New first degree AV block (PR>200ms) or worsening of pre-existing first-degree AV block by >30ms
• New right bundle branch block (QRS>120ms)
• Intra-procedural 2:1 or higher-grade AV block with spontaneous improvement within 24 hours

Exclusion Criteria:

• Patients with high grade or complete AV block post TAVI needing urgent pacemakers
• Patient with existing cardiac implantable electronic devices (CIEDs)
• Patients having a particular medical condition that dictates that they cannot tolerate subcutaneous, chronically-inserted device
• Patient is currently pregnant as evidenced by urine positive Beta-HCG. (Urine Beta human chorionic gonadotropin (HCG) will be checked in all females of the reproductive age group).
• Patients not willing to sign the consent, lacks the capacity to sign the consent or revoke the consent after signing will be excluded

Patients who have undergone Boston Scientific Loop Recorder (LUX-Dx PMA# K193473) as standard of care for arrhyhtmia monitoring after TAVI procedure will have the ILR monitored monthly by the electrophysiology team. All alerts will be reviewed and discussed with the implanting physician for further management. Patients will be followed for up to 12 months.