Heart attack

A heart attack is a serious medical emergency in which the supply of blood to the heart is suddenly blocked, usually by a blood clot. The lack of blood to the heart can seriously damage the heart muscles. If left untreated, the muscles will begin to die. The medical term for a heart attack is myocardial infarction.

Symptoms of a heart attack include:

• chest pain: the chest can feel like it is being pressed or squeezed by a heavy object, and the pain can radiate from the chest to the jaw, neck, arms and back
• shortness of breath
• overwhelming feeling of anxiety

Heart attacks and coronary heart disease

Most heart attacks occur in people with coronary heat disease, which is caused by atherosclerosis. Atherosclerosis is a serious condition where the arteries become narrowed and hardened by the build-up of clumps of cholesterol, called plaques.

The two arteries that supply the heart are called the coronary arteries. People with hardened and narrowed coronary arteries are said to have coronary heart disease (CHD).

Risk factors for CHD include:

• smoking
• high-fat diet
• diabetes
• being overweight or obese

How common are heart attacks?

Most heart attacks occur in people who are over 45 years of age. Men are two to three times more likely to have a heart attack than women.

Treatment options for a heart attack can involve using medication to dissolve any blood clots and surgery to widen the coronary artery.

Outlook

The outlook for people who have a heart attack is highly variable and is dependent on two important factors:

• how quickly they receive treatment after the onset of the heart attack (ideally treatment should begin within 90 minutes of the onset of symptoms)
• how well they respond to treatment within the first 28 days after the heart attack

Currently, just over half the people who have a heart attack die during the first 28 days after the heart attack. Of these deaths, 75% occur in the first 24 hours and 30% of them occur before the person is admitted to hospital.

If a person survives for 28 days after having a heart attack, their outlook improves dramatically and most people will go on to live for many years.

In those who survive a heart attack, a combination of lifestyle changes and medication is usually recommended to reduce the risk of having another heart attack. See Recovering from a heart attack for more information.