I've been to the ER at least 10 times for the same issue. It always checks out fine. I've been to several cardiologists and even had a cardiac cath to make sure there were no life threatening blockages. Of course it all came back normal. Its anxiety...pure and simple. I totally feel your pain.
About 10 years ago, I had the problem you describe. I was given all kinds of heart tests.
Finally they did a heart cath. The whole experience was awful, because I felt no one believed me and actually many thought I was having a panic attack. The day I had the hearth cath, made a call to my Reumatologist, because I knew him better than my primary physician. His nurse had me come to the office right away. He examined me and said it was costochondritis, and prescribed prednisone. I was over it in just a few days.
Then its very likely you have a normal structural heart as confirmed by your normal echo,great too that your holter came back normal,but the thing with 24 hour holter is it only useful to catch those irregular beats while you have those symptoms,if you have non symptoms while wearing the holter then its preety useless.How is ur chestpain feels like ? does it hurt when you press on it ? if it hurts its mostly muscle related not a cardiac related but you also did the right thing by see ing the doctor but once he and your cardiologist cleared that the pain is not related to the heart than you can start seeking counseling for anxiety..as i know it is very horrible that for anyone to have a fear that something is wrong with their heart.
i did a holter an echo back in january and it came back normal also.
Beside doing those blood enzymes and ecg test,did they refer you to a cardiologist for further test like holter,stresstest or and echocardiography ?