I'm a 23 year old male, 171 cm, 57 kg. I exercise four times a week (3 days in the gym, one day of jogging). About 3 months ago my heart suddenly started beating faster and harder. Walking would give me the heartbeat of a run, actually exercising would cause my heart to literally pound, whilst alcohol seemed to make my heart go absolutely nuts. Around the time this started, I had recently broken up with my girlfriend and had had a few late-night drinking sessions, so I figured it might have something to do with stress/lifestyle. I went to the doctors and was diagnosed with a faint heart murmur, but subsequent ECG showed no abnormalities. I am now making efforts to drink less (I would say I definitely drink less than most people my age), eat healthy and relax more, but it doesn't seem to be making much of a difference. At times I seem to be at a shortness of breath, a lot of the time my chest feels rather 'stuffy' and my tolerance for alcohol seems to have gone down - and the hang-overs gotten worse (yesterday I woke up with double-beats). I am having lots of trouble sleeping with this constant awareness and fear that my heart might not be right. A fellow student at my university, 30, recently passed away after a heart attack caused from an enlarged heart. I am now wondering if I might have 'athlete's heart' and if I ought to stop exercising for a while (although I did this the first month after my heart starting playing up)? It has also crossed my mind that I am rather skinny, and that a lack of body fat coupled with a hard training regime might have something to do with it. Has anyone had any similar experiences? Thanks for any comments or suggestions!