Hello,
According to the American Heart Association the warning signs , for heart attack are-
Pressure in chest, pain which can be spreaded to shoulder , arms, and associated numbness,Anxiety, nervousness , sweating.
Also it is possible , that you may not have all the above decribed signs for heart attack.It can be due to anxiety or Acid reflux disease . Exact diagnose will be made after EKG and enzymes levels test.
You should call 9-1-1 , or go to Emergency room ASAP.
Link-http://www.healthcentral.com/heart-disease/patient-guide-44510-6.html
I hope this has helped.