I have been checking out things about flushing for me and a sign of carciniod tumors are flushing and low blood pressure. Pain that goes into your backfrom chest can be pancreatic cancer, it was on Dr. Oz. recently. You may want to make sure your doc does a scan. Not trying to worry you but its better to be safe.
I have the same cest pain/pressure and flushing. It happened also during my tilt table on Tuesday. Sometimes the pain goes around and under my left shoulder blade. When I first noticed it almost a year ago I thought I did something to my shoulder. My holter showed that I had 11hrs and 46min of tachycardia in 48hrs. I also seemed to show abnormal results on the two sweat test. Just waiting for my results and dianosis.
Oh- mast cell activation disorder can cause flushing. Also, I know stress can cause an easy flush as well as tachycardia.
You may want to find out if you have mast cell activation disorder, which sometimes can accompany POTS. Chest pressure/pain can come with the tachy in POTS. If the pain is unrelated to the tachy and your heart has checked out fine with thorough testing (have they done a nuclear medicine test to look for areas of blockage or lack of oxygen in the heart for instance?) and you are not iron deficient (has your doctor checked your ferritin/iron stores and iron levels lately?),
you might consider asking the doctor about :
esophageal spasms which my doctor said can mimic heart pain,
costochondritis, a painful musculoskeletal inflammation problem usually pinpointed on physical exam by the doctor,
and even if you possibly could have a problem with the pancreas, which is behind the stomach organ.
Also, if your anatomical structure is anything like mine, my stomach, according to a technician who did an echocardiogram on me and pressed hard on the area of my xiphoid process to get heart pics, is basically down, right next to my stomach. You might not want to rule out your stomach just yet, even though the meds you took didn't change the discomfort.