What are your experiences out there with pacemaker's ability to prevent AF? In my case, I got a Pacemaker in late September and except for 3 very short episodes in the days immediately following the surgery, there have been NONE! In the weeks before the PM implant, I was having episodes several times a week. My pacemaker has the designed capability to prevent AF but it is not programmed for that and will not be for several more months of healing. And, Medtronics (the manufacturer) says that it is effective only 50% of the time.