What was your open heart surgery exactly? was it a bypass? valve?
I think any time that there are issues w. breathing the first thing that needs to be done is to call your physician immediately before it becomes unmanagable especially if you are having chest pain with this. If it were my body and you are still experiencing these symptoms i would not wait until tomorrow but head to the E,R, tonite if not sooner. Shortness of breath w. chest pain is also a huge red flag......i'l make the call...you didn't say why you had open heart surgery but at this point it really doesn't matter...make the call before things get to a point that they may not be reversible.....time is not something to wait for in this instance