<<Disclaimer: Verify this information before applying it to your situation.>> Thank you so much for your responses and all of your wonderful advice for our daughter. Out of the forty responses that I received, all but about five link the rapid heartbeat to celiac disease and had a marked improvement after starting the GF diet. The remaining ones had thyroid problems except one who indicated a tumor causing the problems and one who had a heart problem that was not found with a normal EKG. If you would like more details, please let me know and I will forward the responses to you privately. Hopefully she will try the GF diet and see if the rapid heartbeat and migraines improve. Thank you again from the bottom of my heart. Barbara in Illinois