 Experience with the LAA occlusion procedure In studies published regarding LAA occlusion, the experience of the interventional cardiologist learning curve and staff was shown to be very important; i.e. the number of complications during the first implantations were significantly higher compared to those that followed. 14, 17 To prevent interventional lack of experience from affecting outcomes, the other two teams will start performing the procedures before the initiation of the study, with the goal of doing at least 5- 10 LAA occlusions before the start of the study. This first 5-10 LAA occlusion will be done not according to the inclusion criteria of our study, but the patients will be enrolled according to the current standard criteria and guidelines for LAA occlusion. Additionally, the first 5-10 procedures in the study will be done with the assistance of an interventional cardiologist experienced with LAA occlusion. 