Hm, if your insurance will let you go to a cardiologist without a referral, there's no reason not to go. If you do want to go to one, you might try to research to find one that has experience diagnosing autonomic nervous system problems. Not saying that's what you have, but I think you would want a cardiologist that would recognize that kind of problem if they see it.

I'm not sure what country you're in, so it's kind of hard to know what to say.