Every year, 805,000 Americans have a heart attack, 605,000 of them for the first time. Infographic by Ruth Basagoitia and Maya Chastain About 12% of people who have a heart attack will die from it.

•It is normal for your heart rate to speed up during physical activity and to slow down while resting or sleeping. •Your heart may beat too quickly, too slowly, or with an irregular rhythm.