What is a heart attack ? Definition of heart attackA heart attack (also known as myocardial infarction or MI) is the damage and death to the heart muscle as a result of a sudden blockage in a coronary artery due to a blood clot . Coronary arteries are blood vessels that nourish the heart muscle with blood and oxygen. Blockage of a coronary artery deprives the heart muscle of blood and oxygen , causing injury to the heart muscle. Injury to the heart muscle causes chest pain and chest pressure sensation. If you do not restore blood flow to the heart muscle within 20 to 40 minutes , causing the death of irreversible heart muscle begin to occur. Muscle continues to die for six to eight hours at a time in which they occurred a heart attack is usually a " full " . The heart muscle is replaced by the dead at the end.
Approximately one million Americans suffer a heart attack each year. Four hundred thousand of them die as a result of their heart infarction .