mayvaj,

Thanks for your question.

I can't say with any certainty what is going on, but there is enough concern for me to say that you should see a doctor at soon as possible.  You may be having a cardiac arrhythmia which is causing your change in heart beat.  Some abnormal rhythms can cause shortness of breath.  Some patients do not experience pain with heart attacks, especially diabetics.

The only way to find out what is going on is to see a doctor who will ask many more questions, examine you, and perform an electrocardiogram.  Then he/she will be in the best position to tell you what might be going on.  More testing may be requested to get to the bottom of things.

Best wishes.

Martin Cane, M.D.