I am a 66 year old female. Went to ER with shortness of breath and chest pressure. Troponins were 73, 76, 84. Did I have an MI?

Yes but. it seems you have the numbers incorrect without a decimal beforehand. Because if your Troponins were really 70s and 80s, you wouldn't need to ask if you had a heart attack. Perhaps they were 0.73, 0.76....