Cytomel (
T3 med) tends to suppress TSH, which is why TSH is not a good indicator of whether or not a person is hyper - again, I'll refer to myself, with a TSH of < 0.01.......
If you think you have a heart issue, by all means see a cardiologist. I had palps, rapid heart rate as well, when I first started cytomel, but once I got used to it, and my levels stabilized, those went away. I did get sent to a cardiologist for a complete work up on my heart, just to be sure..