Subjects consented will be tracked by the study team and will be considered enrolled in this study at the time of the start of their left atrial appendage closure procedure. All subjects that are consented who do not undergo left atrial appendage closure with SentreHeart Lariat® will be considered screen failures. Any patients that have a failed attempt at left atrial appendage closure with SentreHeart Lariat® will be tracked through their index hospitalization for safety; their study follow up will be complete at the time of discharge.