What Is a Heart Attack?

Every year, more than 1 million Americans have a heart attack – a sudden interruption in the heart’s blood supply. This happens when there is a blockage in the coronary arteries, the vessels that carry blood to the heart muscle. When blood flow is blocked, heart muscle can be damaged very quickly and die. Prompt emergency treatments have reduced the number of deaths from heart attacks in recent years.

via Heart Disease Pictures Slideshow: A Visual Guide to Heart Disease on MedicineNet.com.