The heart palps I had while on mirena and for awhile after removal were strange. It was like a sudden adrenaline rush or something. It flushed up thru my stomach and into my heart, making it beat super fast. It's almost like the feeling of when you have to suddenly slam on your breaks to avoid rear ending someone, or I imagine how it'd feel if someone pulled a gun on me. Sometimes it was just mini-adrenaline rushes, and the ones that I describe as panic attacks started with the bigger adrenaline rushes where my heart raced for several minutes afterwards, my hands got clammy and shaky, had shortness of breath. Pretty scary, and I was never doing anything stressful before they would happen, just hanging out or relaxing usually. I'm a pretty mellow person. The doctor did a 24-hour urine test on me, which came up with elevated norepinephrines (a stress hormone) - the only test which ever came back abnormal for me out of many, many tests - so they did a CT scan of my adrenals, which came back normal. These kind of palpitations tapered off in the weeks and months after removal, leaving the anxiety.

The palps now are like an extra beat or thump that feels like it beats out of my chest, almost up into my throat maybe? I don't get the racing heart or anxiety with it, so far anyway.

Hope that helps!
-nile

Glad to hear you are feeling well! I agree that the weird stuff now may just be another shift in hormones... enjoy your pregnancy!