I suffer from panic attacks. have been to er many times fearing heart attack only to be told i am fine. now suffering left arm pain. is this cardiac?

Atypical.....: Left arm pain by itself is atypical for heart pain but not impossible. Are there any associated symptoms with it like shortness of breath? Is it better with rest and worse with exercise? The only way to know for sure if this is cardiac pain is to get an ekg while you are having the discomfort, which may mean going to the er now. Have you had a cardiac stress test recently?

Likely no: You probably have been worked up several times and found that even the risk of heart attack in you is low. An arm pain associated with heart attack will not last so long such as days or even hours without having completed a heart attack and the sequelae such as congestive heart failure would have occurred. Still go to your pmd as reassurance is best if they can review you have been worked up.