I'm 83 Years Old Had 2 Heart Attacks About 25

I'm 83 years old had 2 heart attacks about 25 years ago. Had quadruple bypass operation in 1966. Health and heart have been fine since. Play golf. 3 days ago I was watching TV and felt very tired. I've felt alternately fine and then tired. Blood presssure is 119/68. Pulse is 64. Have no pain but feel tired and somewhat light headed. In 2 weeks, will see my cardiologist. Should I see my regular doctor or go to the ER to check this out before then? Also, what is the name of the procedure that measures blood thru put of the heart?