My 17 year old daughter complained about her racing heart. She passed out in class a couple of times. Went to many Dr's and heart Dr's and they said that it was just anxiety. Finally found a Dr. who would listen to her. She had all the tests done, EKG and halters and kept a mobile ekg monitor with her ( it was just larger than a credit card). If her heart began to race, she would turn on this monitor and place it on her heart. After it recorded, she would call the 800# and send the ekg. A few times the ambulance came to take her to the ER. Finally, we found out that she had SVT, Super Ventricular TachyiaCardia and she ended up having a catheter ablation. Part of her heart had extra muscle tissue that got in the way of the electrical current, so the Dr. froze that part. We were told that this would have happened any time in her life. She is doing very well and on January 17th, she will be celebrating her 22nd birthday!