For the past 17 months or so I have been trying to find a way out of this hell-circle of symptoms that have just befallen me out of nowhere in late 2012.
It all started one day when during lunch my heart started beating much much stronger than normal. I had trouble falling asleep due to the intensity of the beats, but oddly enough my blood pressure and heart-rate were normal (HR is usually pretty low, 50-60). In all this time I have done numerous heart tests (a ECG, 24-hr monitor, treadmill stress test and ultrasound) and they have not found any problems with the heart. Yet, the pounding continues. A couple of months later I have also started getting weird rushes of what felt like adrenaline in my chest, then my heart would skip ocasional beats, or stop suddenly, followed by a rush of some kind where it would restart with the next beat being stronger.
I've done numerous lab tests and the only thing that I can find as problematic is a high TSH (I take NDT thyroid hormones for that which, admittedly, don't do much other than lower my TSH) and I have high cortisol.
I have done norepinephrine and epinephrine tests in urine to rule out a tumor and done an abdominal scan but this all came back normal as well. I also sweat excessively for no reason even when the ambient temperature is fairly low, I am always tired and wired at the same time, can't really relax. Think it's of note to mention that I've been dieting in some way or another since 2009 with sometimes very low calories and alternate day fasting. I have not had health problems before doing these things.
I've experimented with numerous supplements and the only one which helps a bit is taurine.
After a bit of reading it seems that the only things that would lead to an increase in heart contractility would be something that would increase calcium in the heart, like norepinephrine through the sympathetic nervous system. And I believe that is what is involved in some way or the other as all these symptoms came around the same time. I know my hormones are messed up because I have some other apparent problems but the heart thing is bothering me the most. Interestingly the thing that provokes it the most is stretching, that really seems to make it beat like crazy for 20-30 seconds, along with random muscles in my body twitching at a fast rate during that time. It seems like being stuck in some state of overexcitation, and not sure how to proceed from here. Beta blockers would probably be unwise due to the already very slow heart-rate (which I've had even when I was still healthy).