How would you differentiate between costo or a heart attack?

I have costo for around 5 years and every time I have flare ups the same fear comes to my mind - what if it’s a heart attack this time? Symptoms overlap a lot and in case of a heart attack every minute counts. How do you overcome this fear and, what if one day it will be a heart attack and we mistakenly think is costo and seat back and wait for it to go away?