(just got back into town from doing the family thing for the holidays)

I'm an ER doc. I can sympathise with your sister from both the doc and patient point of view. I had similar symptoms, but with a slow heart rate. The short version of this story is that, after a YEAR of trying to figure it out, I ended up with a pacemaker. So I know how frustrating it can be.

I don't know if getting an urgent care/ER referral will work for your insurance. Each one is so different.

Find out from your insurance company what the exact process is to get to a specialist. If you must go through your doctor, make his life miserable until he gives in and sends you to the cardiologist. Or go to a different doc and get the referral. Don't give up on this. Don't let the doctor blow you off. (If my cardiologist hadn't known me well enough to know that I'm not a whiner I can see where it would have been easy to tell me I was fine.)