Hopefully this link works: It s a previous question I asked a while back. http://answers.yahoo.com/question/index;_ylt=AsTZZXHiLp0sZJ5dIuCT1z3ty6IX;_ylv=3?qid=20070803174252AALVJPv I too have been having plapitations, all year in 2005, then they stoped, and came back for all of 2007. Now they have stopped again for the last 5-6 months. I completely understand, they are terrifying. Mine would last ALL day long, one palpitation every three or four beats. The only time they would slow down was if I was actually sleeping. I had a 24 hour holter monitor, which did show the palpitations. Then the results were sent to my cardiologist, and he scheduled an ecg. Of course, I wasn t having any palpitations during the ecg, just like you. My doc told me that I had a mild heart murmur, which he said I probably had since birth. He also told me I had two heart valves which were slightly leaking, and said that it was most definitely NOT life threatening. Honestly I don t really like my doc, but I haven t done anything about it, due to the fact that I have no insurance, and the palpitations have stopped. I also smoke cigarettes, drink coffee, don t really excercise, and drink alcohol 2-3 times a week. So it sounds like you re in much better shape than me. And mine just stopped one day. I am 28 y/o. Unfortunately since I have NO idea why they start and stop, I really can t offer you any advice. It could just be anxiety. I also get occasional panic/anxiety attacks, and my heart palpitates then. I was under A LOT of stress last year, so I think that may have contributed to them. Sometimes I would take Clonopin (spelling?) which is an anti-anxiety medication, and that would relax me and my heart would chill out. Maybe you should talk to your doc about trying xanax or clonopin for anxiety. Even though you may not THINK you are stressed and having anxiety, you just might be. Good luck!!