What is a heart attack?
A heart attack is when the flow of blood to a section of the heart becomes blocked and the heart can’t get oxygen. If blood flow is not restored quickly, that section of the heart begins to die. The level of damage depends on how long blood supply is cut off. The result can be mild damage, or it could lead to severe, lifelong problems.
Signs of a heart attack
Know the signs of a heart attack, you can act quickly to save a life.
- Chest discomfort (uncomfortable chest pressure, squeezing, fullness or pain, burning or heaviness)
- Discomfort in other areas of the upper body (neck, jaw, shoulder, arms, back)
- Shortness of breath
Be aware: warning signs can vary from person to person. The symptoms may not always be sudden or severe.
Chest pain or discomfort is the most common symptom of a heart attack in both men and women. However:
- Some people do not experience any chest pain.
- Some may have only mild chest pain or discomfort.
- Some may experience only one symptom.
- Others may have a combination.
If you experience any of these signs:
- CALL 9-1-1 or your local emergency number immediately.
- Stop all activity. Sit or lie down, in whatever position is most comfortable.
- If you take nitroglycerin, take your normal dosage.
- Chew and swallow Aspirin® (ASA), if you are not allergic or intolerant (either one 325 mg tablet or two 81 mg tablets).
- This can break up the blood clot that is causing the heart attack
- Do not take other pain medications such as Tylenol® (acetaminophen) or Advil® (ibuprofen) instead of Aspirin®.
- Do not substitute Aspirin® for medical care. Call 9-1-1 or your local emergency number first.
- Rest and wait for emergency medical personnel to arrive.
Keep a list of your medications in your wallet and by the phone
Emergency personnel will want this information.
What causes a heart attack?
A heart attack happens when the blood flow through one or more of the coronary arteries is blocked. This stops oxygen from reaching parts of the heart.
More than 9 out of 10 heart attacks are caused by atherosclerosis.
- Atherosclerosis is the buildup of plaque on the inside wall of an artery.
- Over time, the artery can narrow or become blocked.
- This can lead to blood clots.
- Blood clots can become so large, they block blood flow through the artery to the heart.
Heart attack can also be caused by a coronary artery spasm.
- A temporary tightening of a coronary artery
- Can cause flow of blood through the artery to stop.
- Often, the causes of spasms are not known.
Difference between heart attack and cardiac arrest
People often think a heart attack and cardiac arrest are the same. They are not.
A heart attack can lead to cardiac arrest. But they are two different conditions.
- Heart attack: the heart is still beating. Blood is still flowing. The person is still alive.
- Cardiac arrest: the heart has stopped beating. Blood has stopped flowing. The person does not respond. The person is dying.
A heart attack needs immediate medical attention but doesn’t need CPR. A heart attack can progress to become a cardiac arrest, at which point CPR is required.
Difference between heart attack and angina
Angina is the medical term for chest pain. It is not a heart attack. Angina pain:
- Usually goes away with rest or medication.
- Is a warning sign that you are at increased risk for heart attack or cardiac arrest.
Heart attack diagnosis
Your doctor will diagnose a heart attack by assessing your:
- Signs and symptoms
- Medical and family history
- Test results
Common tests include:
- Checks how your heart is functioning by measuring its electrical activity.
- Can detect recent or ongoing heart attack, abnormal heart rhythms (arrhythmias), coronary artery blockage, and areas where the heart has been damaged (from a prior heart attack).
- Can be used to monitor your recovery from a heart attack, the progression of your heart disease, and the effectiveness of your heart medications or pacemaker.
- During a heart attack, the heart releases tell-tale proteins into the bloodstream. Blood tests can identify these.
- Cardiac enzymes found in the blood are often a sign that the heart has been damaged.
- Shows which arteries are blocked and how your heart is working.
- May be done if blood tests or an ECG/EKG suggest you are having a heart attack.
Depending on your test results, your doctor may suggest:
- Surgery or other procedures
- Lifestyle changes and healthier living
Early treatment for a heart attack can prevent or limit damage.
Act fast by calling 9–1–1 at the first symptoms of a heart attack.
- Treatment can begin in the ambulance on the way to the hospital.
Be aware: If you’ve had a heart attack or have heart disease, you’re also at greater risk of stroke.
But there’s good news, too. Maintaining five or more healthy behaviours (not smoking; maintaining a healthy weight, regular physical activity, eating a healthy diet; and keeping high blood pressure, diabetes and cholesterol levels in control) is associated with an 88 % reduction in the risk of death from heart disease or stroke.
It’s normal to feel worried or afraid after a heart attack or heart scare.
You may also have questions:
- Why did this happen to me?
- How will this change my life?
- What can I eat?
- Can I be physically active?
- What are these medications for?
- What about my future?
- Where can I go for more information or for help to get better?
The recovery & support section is full of practical advice and tips to support you on your recovery journey.
We've helped over 800,000 Canadians take control of their risk factors to live healthier, longer lives. Be one of them.
We can help
- Take the Heart&Stroke Risk Assessment. This will give you a personalized risk profile and a customized action plan.
- Download or order our free book Living Well With Heart Diseases. It’s intended for people who have recently had a heart attack or have coronary artery disease.
- Learn the warning signs of stroke.
- Join our community of survivors by signing up for our recovery newsletter. You will get the latest research news, information, tips and strategies to help you manage your recovery.
To find useful services to help you on your journey with heart disease, see our services and resources listing.