The WATCHMAN LAA Closure Technology is designed to prevent embolization of thrombi that may form in the LAA, thereby preventing the occurrence of ischemic stroke and systemic thromboembolism. The objectives of this observational, prospective, non-randomized multicenter study are (1) to compile real-world clinical outcomes data for WATCHMAN LAA (left atrial appendage) Close Technology in patients who are implanted with the WATCHMAN device in a commercial clinical setting and (2) to collect real-world usage data that may be needed for reimbursement of WATCHMAN technology in certain countries.