J.R.
I've done the heart monitor thing a few times. I have always had a very fast heart beat. Ultimately, they discovered it was my thyroid - being hyperthyroid gives you a fast heartbeat so have your thyroid levels checked. Also I agree with the other poster about the liver profile. I was put on Digoxin to keep my heartbeat down and they have to keep an eye on how much it is building up in your liver. Doesn't mean anything is wrong with your liver, it's just a precaution they take. Good luck!