Good point! If one has a short afib then maybe don't know it... So question for experts: HOW LONG DOES IT TAKE FOR A harmful CLOT TO DEVELOP? If we have a SHORT (10 minute? 1 hour? 4 hour?) bout once every 3 weeks, do we NEED a blood thinner? If harmful clot takes 2 days to develop, then these short afib sessions are ok and do not require blood thinners? If not replies, I think I will make THIS a new topic...