Heart Attack

What is a Heart Attack?

Blood Flow to the Heart Is Blocked

A heart attack happens when the flow of oxygen-rich blood to a section of heart muscle suddenly becomes blocked and the heart can’t get enough oxygen. If blood flow isn’t restored quickly, the section of heart muscle begins to die.

Other names for a heart attack are

  • myocardial infarction (MI)
  • acute myocardial infarction (AMI)
  • acute coronary syndrome
  • coronary thrombosis
  • coronary occlusion

(Watch the videos on this page to learn more about heart attacks. To enlarge a video, click the brackets in the lower right-hand corner of the video screen. To reduce a video, press the Escape (Esc) button on your keyboard.)

Affects Both Men and Women

Heart attacks are a leading killer of both men and women in the United States. Each year, more than one million people in the U.S. have a heart attack and about half of them die. Half of those who die do so within one hour of the start of symptoms and before reaching the hospital.

The good news is that excellent treatments are available for heart attacks. These treatments can save lives and prevent disabilities.

Prompt Treatment Is Important

Heart attack treatment works best when it's given right after symptoms occur. Prompt treatment of a heart attack can help prevent or limit damage to the heart and prevent sudden death.

Call 9-1-1 Right Away

A heart attack is an emergency. Call 9-1-1 right away if you think you or someone else may be having a heart attack, even if you’re not sure. You also should call 9-1-1 if your chest pain doesn't go away as it usually does when you take medicine prescribed for angina (chest pain).

Do not drive to the hospital or let someone else drive you. Emergency personnel in the ambulance can begin life-saving treatment on the way to the emergency room. They carry drugs and equipment that can help your medical condition, including

  • oxygen therapy
  • aspirin to prevent further blood clotting
  • nitroglycerin to reduce your heart’s workload and improve blood flow through the coronary arteries
  • treatment for chest pain
  • defibrillators that can restart the heart if it stops beating.

If blood flow in the blocked artery can be restored quickly, permanent heart damage may be prevented. Yet, many people do not seek medical care for 2 hours or more after symptoms start.