Left Atrial Appendage Occlusion (LAAC) with Watchman FLX. for Leakiness

The current standard of care for patients who underwent left atrial appendage closure (LAAC) is to have follow-up transesophageal echocardiogram (TEE) for device surveillance. TEE is an ultrasound of the heart done by placing a probe in the esophagus under conscious sedation. It does not use contrast but can be cumbersome to patients as it involves placing a probe in the esophagus. Cardiac computerized tomography angiography (cardiac CTA) is a non-invasive imaging modality that involves the use of certain types of x-rays, contrast (dye) and special computers to generate accurate images of the heart. Participants in this study will undergo both TEE and CTA on the same day 90 days after their LAAC procedure. Participants will be in this research study for a period of 1 year, starting from the day of their scheduled LAAC procedure. Participants will undergo a TEE at 90 days after their procedure which is the standard of care imaging study after LAAC. As part of this study, participants will also undergo a cardiac CTA at 90 days as well. Participants will have a routine follow-up visit following device placement as per standard of care as well as a brief phone "check in" at 1 year.