@janiem07
Yes I have been told I have long QT.

Are you seeing a EP? If not would suggest you can see one as they are specialists in electrical functions of hearts.

Seems from your post though you have a thorough cardiologist and giving you many tests to help diagnosis.
Ask your cardiologist if any of your medications could be contributing to your Long QT.

I point this out as my psychiatric medication specialist (treating my PTSD anxiety/panic disorder) wanted to put me on a anxiety medication but said it can cause a longer Q wave of some kind (I am not sure exactly which wave). She got concurrence from my HF and EP that it would not affect the function of my heart and was okay to prescribe.