Heart Attack

A heart attack (also known as a myocardial infarction) is the death of heart muscle from the sudden blockage of a coronary artery by a blood clot. A coronary artery is a blood vessel that supplies the heart muscle with blood and oxygen.

Heart Attack

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 the sensation of chest pressure.

If blood flow is not restored to the heart muscle within 20 to 40 minutes, irreversible death of the heart muscle will begin to occur. Muscle continues to die for six to eight hours at which time the heart attack usually is "complete". The dead heart muscle is eventually replaced by scar tissue.


What causes a heart attack?

The most common underlying disease for heart attacks is atherosclerosis, where fatty plaques build up on the inner lining of the coronary arteries.This is known as coronary artery disease (or coronary heart disease), and is a gradual process that slowly limits the blood supply to the heart muscle. The biggest single risk factor for heart attack is smoking.

Other causes include:


Signs and symptoms

Some heart attacks are sudden and intense, but most heart attacks start slowly, with mild pain or discomfort. People often are not sure what's wrong and wait too long before getting help.

The warning signs of a heart attack vary, it is possible to have no pain (especially in women and people who are diabetic) or the only sign may be an indigestion type pain. If you have chest pain which lasts more than a few minutes it MAY be a sign of a heart attack.

The pain may:

  • initially come and go
  • be in one or both arms (more commonly the left)
  • go into your neck, back, jaw, stomach and abdomen

It may feel like:

  • squeezing
  • pressing
  • tightness
  • fullness
  • pain

You may have one or more of the following symptoms with or without chest pain/discomfort:

  • sweating
  • feeling faint
  • feeling sick
  • vomiting
  • being short of breath

Learn the signs, but remember: Even if you're not sure it's a heart attack, have it checked out.

Minutes matter! Fast action can save lives - maybe your own. Don't wait more than 5 minutes - call 111.
Calling 111 is almost always the fastest way to get lifesaving treatment. Emergency medical services staff can begin treatment when they arrive - up to an hour sooner than you'd get treatment if you go to hospital by car.


How is a heart attack diagnosed and treated?

The diagnosis of heart attack is based on your symptoms, your personal and family medical history and the results of diagnostic tests.

Once you are at hospital:

  • You will be treated in the emergency department. The doctors will need to find out whether or not you’ve had a heart attack.
  • Tests will include an ECG and blood tests for cardiac enzymes (cardiac enzymes are released into your body by damaged heart muscle cells)
  • You will be given drugs to help you recover. These may include a thrombolytic drug which will help to breakdown the clot.
  • You may need an angioplasty.

Once your condition is stable you will be transferred to a specialist ward called the Coronary Care Unit (CCU). As your heart becomes more stable the ECG monitoring will be taken away. You will be able to walk gently around the ward with assistance. You may be given medication as well as being prescribed aspirin, which helps to reduce your risk of more clots developing. Further blood tests will be required before you are able to leave and if there are no more problems you can look forward to going home in a few days.

Next steps

What can I do to reduce my risk of having another heart attack?

Cardiac rehabilitation is an important part of recovery and can significantly increase your chances of recovering successfully and avoiding having another heart attack.

Download our resource Reducing your risk of heart attack or stroke. Click on the image below to pre-view a full-screen version of this resource.

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