This has been happening to me too.  Mine starts out as a chill up my spine and then it feels like my blood drains from my upper body.  I can't find a pulse so I panic and stand immediately.  So far this has worked for restarting my heart.  It then beats very fast and afterwards I shake for a while, like someone who is cold, but I'm really hot.  I have had all kinds of tests run from EKG, EEG, CT Scan, Upper GI, to bloodwork and glucose tests.  Nothing has been found.  I'm scared to stay alone because I get so weak when they do happen.  Please let me know if you find out anything.  Thanks!

Hello. Well, gosh, it sounds like something I get once in a while, but I noticed mine happening when I haven't been eating well enough. I think when you feel like your heart isn't beating, it is, but it is going into a type of a very soft, rapid, beat (and no, you can't feel it). What it is, with me anyway, is called heart palpitations. It doesn't happen often in me either. However, my mother gets them so often and so badly that they had to put her on special medication to keep it steady and normal. She's had them for 40+ years and when you get them often, like she did, it causes the heart to get weak. But, mine, happens when I find myself not eating properly, or when my blood pressure rises (like you do when you feel stressed about this and things in life). My doctor put me on a medication called 'atenolol'. It regulates my blood pressure, which stopped the heart palpitations. Sometimes I get them when I haven't eaten for a long period of time, eat, and then that fluttering, skipping, hard to breathe feeling comes. Believe me, when that happens, I wished my foot could reach my hiney a little easier. I feel like kicking myself for not taking care of my body the way I should. Now, I don't know what your eating habits are, but I do know that if you are stressing, it can happen too. I bought a blood pressure band that fits on my wrist through one of those health magazines. When I feel my heart doing that, I take my blood pressure and find it way bad. So, if you can find one of those in a health store or magazine, internet.. get one. They're not all that expensive. And, take care. Don't stress.. yeah, I know.. easier said than done.. I'm sorry.. I hate it when people tell me that too... but, don't stress.. lol. Enjoy life, and if it starts doing this more often, go back in and talk to you doctor again.. k? you just take care now.. Don't be afraid. I wish there was a way you could keep us posted, but I do have Yahoo 360. I'm trying to figure out IM..