I have similar symptoms (usually when falling asleep at night). I'm 34, ~150 lbs., mostly inactive (have a desk job). Have you had/have metal fillings, or lyme disease? Just wondering, as I have had both. I have found that how tired I am does not seem to affect the symptoms. I have had insomnia and similar brain disturbance symptoms since I first experienced the heart symptoms (about a year ago), so I wonder if it is related. Do you have any insomnia/severe depression/any other weird brain symptoms? Take care.