The first question I have is how did the tests turn out that happened a year ago? IF those turned out normal, what you have is a classic case of anxiety w/panic attacks. Every single symptom you have mentioned are those of this disorder. In fact, when reading your post, it is almost as if I was reading my own story. I went through the exact same thing - including the ER visits, tests, symptoms, etc.
More than likely the tachycardia is caused by the anxiety/panic which causes more panic, and it hence is the cycle. If it makes you feel any better, here is the way I look at it. (If the doctor does say you have clean tests and EKG like you said).
a.) If this is something that happens frequently, then it would definately show up on the EKG, it could not hide itself.
b.) Unless you have a genetic history of heart conditions, you are probably not suffering from something rare - it is MUCH more likely that it is panic/anxiety.
c.) a human heart is a very very strong and thick muscle; in fact, most people do not realize that it could last at nearly 250-300 beats a minute constantly for hours and hours without any damage at all. (I realize that doesn't make it any more comfortable!).
If you could, reply as to how the tests turned out last year and recently and I will add more information that can help. (You may also want to read my profile)
In addition, read through as many posts on here as you can and you will see that there are MANY people who feel the same way you do and think that they have heart problems, when in fact they do not. Good luck!
Thanks so much all of test were normal said I had MVP (mitral valve prolapse) and very small ASD (atrial septal defect)
I understand what you are going threw I have four kids and I have had
the same thing, when you feel the racing you can take a couple deep coughs or massage one side of your neck where the artery is or you can drink some ice water this should slow your heart rate down, you should try not to panic over it, it only makes it worse
I have almost the exact same story. 2 years ago I went to the emergency room and all the tests came back normal. I have been on 25mg of Toprol. I was able to go off of it for six months. Suddenly all of my symptoms came back. I have a hard time believing it is not my heart, but I have just started therapy to help me deal with it. It does help to know that there are so many of us going through the same thing.