Is it true that the symptoms of a heart attack appear much before it actually happens?

Not all people who have heart attacks have the same symptoms or have the same severity of symptoms. Some people have mild pain; others have more severe pain. Some people have no symptoms; for others, the first sign may be sudden cardiac arrest. However, the more signs and symptoms you have, the greater the likelihood you're having a heart attack. Some heart attacks strike suddenly, but many people have warning signs and symptoms hours, days or weeks in advance. The earliest warning might be recurrent chest pain or pressure (angina) that's triggered by exertion and relieved by rest. Angina is caused by a temporary decrease in blood flow to the heart.