I am a 22 year old in the army who returned from overseas late last year. I took 3 ambien on the 14 hour flight back, had a six pack of beer with the guys, and went to sleep. The next day I woke up, drank an energy drink (which I have been drinking at the rate of one to two a day for the past 2 years) and suddenly had a really tachy heart beat and a faint radial pulse. I went to the ER and the ECG came back normal. Over the next month I had 5 more ECG's, 2 blood tests for thyroid irregularities, a chest X-ray, a 24-hour Holter monitor, an MRI, and a stress test. All came back clean. While this should be comforting, over the past few months I still feel like my heart is beating either too slow or too fast, too faint or too strong. I feel faint for no reason, and occasionally experience skipped beats. It's bad enough that I don't feel comfortable being by myself for fear of something bad happening and not being able to deal with it. Does anyone have some insight as to what it could be, or a good course of action to deal with it? Keep in mind, in the military you need to get a referral to be seen by a full blown doctor, and since they have run the course with cardio tests, I am afraid the next PHD they send me to will be a psychiatrist. Thanks.