chest in my chest

for like 4 years now i feel a pain in my chest that really bother me alot and also my left arm every now and then but my left arm dont hurt it just feel weird like i cant even explain it myself how it feels and most of the times it happen when im goin to sleep or just if im like sitting down or relaxing but i been to the hospital alot of times thinking is a heart attack or something and they have done x-ray and blood test and the only thing they told me was that i have heart palptations but nothing serious and they also gave me a appointment with a cardiologist to get check up even better just too make sure everything is all rigth but i didnt go and that was like 5 months ago in december 26 of 09 now is june 5 2010 and still happens every now and then so anybody has the same feeling?????????