I haven't been formerly diagnosed with Atrial Fibrillation or a heart murmer, but from everything I read on the net of the symptoms, I can almost bet that I have A.F. I ended up in the E.R. one time because my heart was racing and wouldn't stop, but before that happened I noticed my heart missing beats, then thudding afterwards, and being light headed during those times. Then I started smoking weed, and during the 6 months that I did, those symptoms went away. I didn't attribute that to smoking until I quit and the symptoms returned. At that point I began to wonder if weed helped. I started smoking again, and just a month ago, I quit again. Sure enough - the symptoms have returned in full force. I have searched the net for stories of this happening to other people or studies done in reference to this, but I can't find any! I would like to know if anyone has heard of this happening to anyone before?