The worst news possible for me

I had my followup appointment with the cardiologist today. Last week I had to do a stress test and Monday I had an echocardiogram. The stress test was abnormal and the echo revealed that my ejection fraction is half of what it should be for my age. The doctor now wants to do a heart catheterization to make sure I don't have a blockage. I also have cardiomyopathy, which is what my mom died from 6 years ago. I'm so completely numb that I don't know what to do. I'm not going to tell my grandmother (mom's mom) because I don't want her to worry. That's about it for now. I think I'm going to go to bed and try to forget today happened at all.