Heart attack symptoms not heart attack

Hi,
I am 32 years old, and have previously had some cardiac issues, resulting in surgery in 97. Over the last couple of years it appears that due to the surgery I have been getting AF when the scar tissue short circuits the electrical current, requiring Cardioversion to rectify as I do not responde to medication.

The other night I had sevear chest pains, including in the jaw and left arm. I was admitted into the hospital for the night with a suspected heart attack, however the ECG was all fine, the blood tests did not indicate any stress etc, so I was realeased.

The Dr said he was sure it was not a heart attack, but was not comfortable claiming it was indegestion (which I have never had), but rather he did not know what it was.

My muscles are now very sore, like I have been lifting heavy weights (or how they feel after cardioversion), and I had similar, but much milder pains last night.

I have now also got pins and needles in the left arm down to the finger tips (although I do not know whether or not this has to do with RSI) for the last 5 hours or so consistently.

Any idea of what is going on...is it nerural, or should I go back to Dr?

Many thanks

Kirsty