What does it mean to have a heart attack?

Heart attack symptoms can be severe or subtle. The underlying process that causes a heart attack can differ, and people may experience significant heart damage or little to none. Doctors diagnose a heart attack based on symptoms, a person’s cardiovascular risk profile, electrocardiogram findings and the blood troponin level. Troponin is a protein released when heart damage occurs. Immediate and long-term treatment depend upon the type of heart attack and its impact on heart function.