Heart attack | Hē manawa

Also known as a myocardial infarction (MI)

A heart attack (hē manawa) occurs when blood flow to a section of heart muscle becomes blocked. If the flow of blood isn’t returned quickly, the section of heart muscle becomes damaged from lack of oxygen and starts to die.

Key points about heart attack

  1. Heart attack symptoms vary. Some are sudden and intense but most start slowly, with mild pain or discomfort that can be easily mistaken for indigestion
  2. If you have severe chest pain for more than 15 minutes, assume it's a heart attack.
  3. A heart attack is a medical emergency and you need immediate medical help.
Symptoms of heart attack vary. However, if you have severe chest pain for more than 15 minutes, assume it's a heart attack, and do the following:
  • Call 111, ask for the ambulance service and tell them you are having a possible heart attack.
  • If available, chew one aspirin, unless you have been previously advised not to take aspirin.
  • Rest quietly and wait for the ambulance.
  • Get someone to wait with you, if possible.
  • Remaining calm means you are less likely to suffer some of the heartbeat disturbances that create problems for you and your immediate medical advisors.

What are the signs of a heart attack?

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Some heart attacks are sudden and intense but most heart attacks start slowly, with mild pain or discomfort that can be easily mistaken for indigestionSymptoms often differ between men and women. Often an attack is triggered by some form of exercise or heavy work but this is not always the case.

Chest pain/discomfort

If you have chest pain that 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
  • also feel like squeezing, pressing, tightness or fullness.

Symptoms in women

Chest discomfort may not be the worst, or most noticeable, symptom in women. Women are more likely than men to experience the following symptoms, with or without chest pain/discomfort:

  • sweating
  • feeling faint
  • feeling sick
  • vomiting
  • being short of breath
  • palpitations (a noticeably fast, strong or irregular heartbeat).

You may not experience all of these symptoms. If you are experiencing some of them call 111 without delay. See also why women ignore heart attack symptoms.

What is the treatment for heart attack?

A heart attack needs urgent medical attention. If you think you are having a heart attack:

  • Call 111 and ask for an ambulance and let them know you may be having a heart attack.
  • If available, chew one aspirin, unless you have been previously advised not to take aspirin.
  • Rest quietly and wait for the ambulance.
  • Get someone to wait with you, if possible.
  • Remaining calm means you are less likely to suffer some of the heartbeat disturbances that create problems for you and your immediate medical advisors.

See also action plan for heart attack and treatment FAQ.

What is cardiac arrest?

During a heart attack, part of your heart is starved of oxygen. Heart muscle is especially sensitive to a drop in oxygen carried in your bloodstream. This drop can interrupt your heart's rhythm and can cause it to suddenly stop beating. This is known as cardiac arrest. Cardiac arrest is life-threatening and requires immediate medical attention. Read more about cardiac arrest.

What causes a heart attack?

For many New Zealanders, a heart attack happens out of the blue. But it is usually the result of 3 processes:

  • the development over many years of fatty deposits (plaques) on the walls of your arteries  
  • a clot forming on one of the plaques, resulting in a blockage of that artery
  • the blockage stopping blood flow to a section of heart muscle and, sometimes, the electrical impulses your heart responds to also stop working properly.

Read more about the causes of heart attack.

How can I decrease my risk of having a heart attack?

A number of factors increase your chances of developing coronary heart disease. The more risk factors you have, the greater your chance of having a heart attack. You can’t change some of your risk factors – such as your age, sex, ethnicity and family history – but there are many others you can, such as smoking, blood pressure, weight, activity level and how much alcohol you drink.

Making positive changes to reduce the impact of these risk factors have will dramatically reduce your risk of cardiovascular disease and heart attack.

Read more about heart disease risk factors.

Learn more

Heart attack Heart Foundation, NZ
Heart attack NHS, UK
Heart attack – explained American Heart Association, US

Reviewed by

After 45 years of GP experience, and 8 years as an examiner and practice assessor, Dr Bryan Frost has completed a Diploma in Editing and is pursuing a new career. He also has a Diploma in Health Administration, with honours in management, and has also completed a paper in Health Care Law.
Credits: Health Navigator Editorial Team. Reviewed By: Dr Bryan Frost, FRNZCGP, Morrinsville Last reviewed: 27 Jan 2021