What is a heart attack?

To work properly, your heart needs a continuous supply of oxygen-rich blood. It normally receives this from blood vessels called coronary arteries. When a coronary artery suddenly becomes completely blocked, oxygen can’t get to your heart muscle — which causes a heart attack (or, ‘myocardial infarction’).

Heart attack is a medical emergency: without oxygen, the muscle begins to die and your heart can become permanently damaged.

Heart attacks can be fatal — every day, 21 Australians die from heart attack. One patient is admitted to hospital due to heart attack every 9 minutes.

What are the symptoms of a heart attack?

If you have any of the symptoms below, you could be having a heart attack. If symptoms are severe, get worse quickly, or last longer than 10 minutes, call triple zero (000) immediately and ask for an ambulance. If calling triple zero (000) does not work on your mobile try calling 112.

The most common symptoms of a heart attack include:

• chest pain (angina) — pressure or tightness in the chest and arms that may spread to the jaw, neck or back
• suddenly feeling dizzy, faint, light-headed or anxious
• nausea or vomiting
• indigestion or heartburn
• sweating, or a cold sweat
• shortness of breath or difficulty breathing

Women may experience different symptoms, such as:

• breathlessness and generally feeling unwell
• tightness or discomfort in the arms
• back pain or pressure

Heart attack symptoms differ from person to person. Some people experience no warning signs before a heart attack while others feel symptoms days or weeks in advance. Nearly 1 in 3 men and nearly 4 in 10 women who have heart attacks don’t feel any chest pain at all. Chest pains may also come and go.

What causes heart attacks?

The most common cause of a heart attack is coronary heart disease. This is where fatty deposits, cholesterol and other substances build up in the walls of the coronary arteries that supply oxygen to the heart. Over time, this build-up hardens into plaque that can break off at any time and cause a blood clot which blocks the artery.

In some cases, heart attacks have another cause:

• Coronary artery spasm (variant angina) is an unusual narrowing of blood vessels that can stop blood flow to the heart.
• Spontaneous coronary artery dissection is a sudden tear in the wall of a coronary artery, which can also affect people who have few risk factors for heart disease.

Certain lifestyle factors are shown to increase your chances of heart disease and having a heart attack.

• Smoking damages your blood vessels and makes you 3 times more likely to die of a heart attack.
• An unhealthy diet high in saturated fat, salt and added sugar puts you at risk of heart disease.
• Not enough physical activity — more than 4 out of 5 Australians aren’t physically active enough.
• High blood pressure — 1 in 3 Australians live with high blood pressure.
• High cholesterol — too much ‘bad' LDL cholesterol in your blood is one of the main reasons for a build-up in fatty plaques that block your arteries.
• Diabetes — people with diabetes are up to 4 times more likely to have a heart attack or stroke.
• Unhealthy weight — people who are overweight or obese have an increased chance of having a heart attack.
• Poor mental health — conditions such as depression can increase your risk of heart disease.

When should I see my doctor?

Call triple zero (000) immediately and ask for an ambulance, if you or someone near you experiences symptoms of a heart attack that are:

If calling triple zero (000) does not work on your mobile, try calling 112. Early treatment could save a life.

See your doctor regularly to manage your general health, test for heart disease risk factors and help you take steps to prevent a heart attack.

How are heart attacks diagnosed?

If you think you might be having a heart attack, you need to head to a hospital straight away. There, a doctor will assess your symptoms and check your vital signs – blood pressure, pulse and temperature.

There are several tests that help indicate if you’ve had a heart attack, and whether damage was caused, such as:

• electrocardiogram (ECG) — electrical leads are placed on your chest, arms and legs to record the electrical signals travelling through your heart muscle
• blood tests
• chest x-ray
• angiography (or, coronary catheterisation) — a special fluid is inserted into a blood vessel through a small tube (catheter) to show whether your coronary arteries are narrowed or blocked
• exercise stress test
• CT scan or MRI scan

How are heart attacks treated?

The first step in treating a suspected heart attack is to restore blood flow to the heart quickly. Heart muscle cells depend on oxygen and the longer the heart is without oxygen, the more permanent and widespread the damage.

Medications

Treating a heart attack often involves dissolving any blood clots blocking blood flow with medicines called thrombolytics.

Other medications may be prescribed to help reduce the risk of another heart attack. These include:

• medicines that reduce the blood’s clotting action such as aspirin, anticoagulants (blood-thinning medicines) and anti-platelet agents
• medicines to lower blood pressure (for example, ACE inhibitors and angiotensin II receptor blockers)
• beta blockers to slow your heart rate

Surgery

Surgical procedures can help to restore blood flow to the heart, including:

• Coronary angioplasty — a procedure in which a coronary artery is opened up from the inside using a special balloon inserted through your groin or wrist. The artery may then be kept open with a special metal tube (stent) left inside your artery.
• Bypass surgery (coronary artery bypass graft surgery, or CABG) — involves redirecting blood to bypass (go around) the blockage in the coronary artery and improve blood flow to your heart.

How can I prevent a heart attack?

Making positive lifestyle changes is the best way to lower your risk of a heart attack.

There are a number of ways you can improve your heart health:

• quitting smoking
• eating a healthy diet
• seeing your doctor to help manage your cholesterol and blood pressure
• staying physically active and exercising regularly
• maintaining a healthy weight
• drinking alcohol in moderation
• reducing stress and looking after your mental wellbeing

There are also other risk factors that you can’t control, like your age, gender, ethnicity and family history.

Speak with your doctor if you’re concerned about your risk factors, and for tips on how you can reduce your risk.

Are there complications of a heart attack?

Complications following a heart attack can include:

• Arrhythmia — your heart may develop an irregular heartbeat following a heart attack due to damaged heart muscles disrupting electrical signals.
• Heart failure — your heart may have ongoing difficulty pumping enough blood, due to its muscles being too weak or stiff.
• Cardiogenic shock — where your whole body goes into shock from extensive heart muscle damage.
• Heart rupture — this is a rare but serious complication in which the heart’s muscles, walls or valves split apart.

These can be dangerous if untreated, but your healthcare team will help to manage them if they occur.

Is a cardiac arrest the same thing as a heart attack?

A cardiac arrest and a heart attack are both medical emergencies. However, they are not the same thing, and sometimes a heart attack can progress into a cardiac arrest.

During a cardiac arrest, the electrical system that controls your heart rate and rhythm stops working, and the heart stops beating.

When someone has a cardiac arrest, they experience different symptoms and receive different treatments to someone who has a heart attack.

Someone having a cardiac arrest will collapse and have no pulse. They may not breathe properly, or maybe not at all, and they will lose consciousness.

If someone has a cardiac arrest, they need help immediately. Call 000 (triple zero) for an ambulance. While waiting for the ambulance to arrive, begin chest compressions (cardiopulmonary resuscitation or CPR), or use a device called a defibrillator, if available. Once the person gets to hospital, a medical team will treat them.

Does COVID-19 cause heart attacks?

Research so far suggests that COVID-19 mostly affects the lungs, but it can also affect the heart and worsen existing conditions.

See the Heart Foundation’s FAQs page for more information about COVID-19 and heart disease.

Life after a heart attack

Recovering from a heart attack can be both emotionally and physically challenging. Hearing stories from others who have experienced a heart attack can help.

The Heart Foundation have shared several people’s “heart stories” on their website.

Resources and support

For more information and support, try these resources:

• Download the Heart Foundation’s heart attack action plan to understand and be ready for any warning signs of heart attack.
• Call the Heart Foundation Helpline on 13 11 12 for more information on heart health.
• Read about the Victor Chang Research Institute’s projects on coronavirus (COVID-19) and heart disease.

Other languages

Do you prefer to read languages other than English? The Heart Foundation has fact sheets on heart health translated into more than 25 languages.