I Have Heart Disease.....and For 2 Day's I'm Having Pain

I have heart disease.....and for 2 day's I'm having pain on the back of my shoulder......and all this is making my right arm have a dull ache.....I also feel Nausea.....but have not thrown up...... Could this be some blockage??? My age is 73...... I had open heat surgery 4 years ago.....