Yes, they are considered the silent heart attacks or a mild heart attack but are as important to be concerned about since a heart attack does damage to the heart and can eventually be the start towards a big one. If you have one don't be too concerned because you can start with a good diet, take aspirin, and take better care of yourself but see your Doctor for sure and follow directions! Take care.
Absolutely, or at least you ignore it because you don't want to upset anyone in case it is only indigestion. My father had a massive heart attack about 5 years before he died. When he went to the hospital they ran an EKG and determined that he had had several smaller attacks over the preceding years. He did not see a doctor on a routine basis for check-ups or anything. If you are concerned that you might have had a heart attack - GO TO YOUR DOCTOR!
Yes. It's called a "Silent Heart Attack.
The is a measurement called a "Q" wave. It can give a false positive, so you may not have had a heart attack.