I have had the same exact symptoms and feelings as everyone here has described. (dizziness, fainting, and like a jolt of electricity in my chest which jerks me awake/kicks my legs, back or even makes me sit up.) I've had this sleep issue at least 3 times / week (and it can happen all night long sometimes) since POTS started for me in May 2009, so I'm really tired! lol I've been to Dr. Grubb (awesome man), as well as my regular ElectroPhysiologist, and some other cardiologists who told me: Take melatonin and/or magnesium to help with sleeping. Some doctors have just dismissed the entire complaint not knowing what to say and making me feel like I'm crazy. One doctor said I should do a sleep study (which was what I was hoping he'd say), but sadly, my COBRA ran out and now I have only emergency medical insurance, so that is on hold. One doctor friend suggested taking benedryl, which has helped on occasion, but I don't want to keep taking meds for it. I used to be a serious ballet dancer, so I've been incredibly aware of what my body feels. It can get frustrating when I definitely know what my body is telling me, yet the doctors dismiss or don't believe what I'm saying. To help with this fainting/jumping issue while sleeping, I try to be loaded up on G2 before bed, always have a bottle nearby, and generally will drink a cup of buillon before bed when I feel it's going to be a rough night. I have also slept with my head raised up since the start of POTS when I told a doctor this, he scoffed and said: Raising the head of the bed is just for adjusting Potsies to being upright already when they wake up before getting out of bed. I decided to sleep elevated because of precisely the sleep issues listed in this thread. After charting everything from diet to BP and HR daily for 9 mos, I came to the conclusion that sitting up while sleeping was better than laying flat for me because my BP would drop way too low. Then my heart kicks in and will go 150 bpm to get the blood flowing (which may explain the reason some of you feel out of breath). I would sleep with a heart wrist monitor on, as well as keep my BP cuff on while sleeping. As soon as I'd get the jolt awakening me, I'd hit the buttons to see where BP and HR were. Sure enough, low BP and high HR. Caught red-handed! lol I am currently off all medications for just over one year now. Aside from this sleep issue, I now only feel symptoms when it rains/weather systems move through. And now, I'm going to knock on wood! lol I have to say thank you to Atomic811 for starting this thread, because I've been dealing with this issue for 2 1/2 years now, and feel like I'm the only person on the planet like this. I'm really sorry you're all experiencing it too, but it is a relief to know that I'm not crazy...entirely...lol. Good luck to everyone! Will post if I find anything else that helps!