I have been having a rapid heart beat with what feels to be muscular chest pain. I went to the ER a few days ago for it. The did an ekg, CT scan, and a cbc and said everything looks good. No signs of CAD, embolism, or anything else. I have an overall unusual feeling in my stomach and chest. The ER doctor recommended to see a cardiologist because my heart rate is so high at rest. I know it's not life threatening, or I wouldn't have been sent home and told I am healthy on paper. My question is, what could be causing this? And what will a cardiologist look for that ER didn't? I am a 32 yo female, smoker, and overweight.