Structural normal heart/previous myocarditis/PVC

I am a female, 46 years,and have a history of periodic frequent PVC:s and two years ago I also was diagnosed with EAT. The EAT-attacks can come several times a day, but are of a short duration and do not bother me much. I take metoprolol and that helps a bit.  The PVC:s are another matter. They often come when I move around and try to exercise and when I performed a stress test a couple of months ago the record showed two couplets of PVC, low exercise tolerance and ST-depression. I then did a nuclear stress test a couple of weeks ago and that came back normal: It dit not show any signs of CAD and the blood flow in the heart muscle was normal. That was a releif, but I am still worried. I sometimes experience a different kind of tachycardia that does´nt feel like EAT and am afriad that it is VT. Each attack last about five or ten seconds and than terminate. I have read that PVC and NSVT is safe in the settings of a structurally normal heart and my myokardial scint did not show any damage. The thing is that my doctor suspects that I have had myocarditis a long time ago and that is what caused my EAT by creating some small scar tissue. My questions are:
1- Does my heart fall in the cathegory structurally normal (since av don´t seem to have CAD and normal heart muscle structure showed by the nuclear test)  in spite of my presumed previous myokarditis ?
Or is it possible that i have small scar tissues in the lower heart chambers that starts PVC:s (NSVT has not shown up in any tests, that is still just a worry in my head)?

2. In that case: Is the couplets of PVC:s (and possible NSVT) a bad sign and dangerous?
I am still a bit scared for exercising but have began to slowly build up my shape again.

Thanks

[Eva_C]

Hoping for an answer soon...