<<Disclaimer: Verify this information before applying it to your situation.>> I have a history of tachycardia and recently spent a night in the hospital when I experienced chest pain. As it turned out, it wasn't heart-related but was a spasm of my esophagus. This can be triggered by acid reflux. I'd eaten Mexican food the night before and, although it was "safe," I don't often eat spicy food. Also, whenever I do have a gluten accident I get a lot of acid. Anyway, the pain went away immediately when I was given nitroglicerine, which I understand is normal, and I'm now being treated for GERD (gastro-esophageal reflux disease). Hope this helps.