Dear wehaveplans,
I hope you are feeling better. I know exactly what you are going through. The first time I felt those thumps, jumps and jolts
I immediatly felt a rush of adrenaline. I felt hot and started to panic. i rushed to the ER just to be told "you just have anxiety"
try not to stress. Well -how can you not stress when you feel something may be wrong with my heart- The Dr's give me valium and yes they (thumps) go away. Now, I am going thru it again. This time because I am weaning off of anti-anxiety med's (kinda double edge sword at times) I have been getting them alot lately. They have been evaluated thru holter just like ur's and I was told
they may be PVC- Premature Ventricular Contractions a relatively benign heart condition that lots of people have but cant feel. Man I wish I were one of those people 
Listen, I know its hard but we can find support in each other -let's get these dr's to do what they need to do and us
to get in shape and our hearts stronger.
Try walking 20 minutes a day. I will if you do. Let me know. i am here for You!!!!
Tai