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What is Sudden Cardiac Arrest (SCA)? What to do When Someone Goes into SCA

man holding chest

When a person experiences a heart episode it can be very frightening. It can be even more frightening if you’re there with someone who experiences a heart episode. Would you know the difference between a person who goes into Sudden Cardiac Arrest (SCA) versus someone who’s having a heart attack? If someone goes into SCA would you know what to do to help them?

According to the Heart and Stroke Foundation, 8 in 10 SCA events occur at home or in public places, 1 in 10 if those survive.

Learning First Aid and having an AED in close proximity to someone experiencing SCA will increase their chances at surviving. In fact, double the number of people survive SCA when immediate action is taken.


What is Sudden Cardiac Arrest?


Sudden cardiac arrest happens quickly and without any warning. When it does happen, it’s crucial to act immediately to help the person. Sudden cardiac arrest is when heart function becomes almost non-existent, and a person’s breathing and consciousness come to an abrupt stop. This is typically caused by an electrical disturbance (arrhythmia) in the heart that affects its ability to pump blood into major organs like the brain and lungs. SCA basically causes the blood flow to stop in the body. If the victim does not receive treatment right away, death can occur within minutes.


What is the Difference Between Sudden Cardiac Arrest and a Heart Attack?

While Sudden cardiac arrest stops heart function completely, a heart attack happens when a person’s artery becomes blocked, preventing oxygen-rich blood from reaching the heart. When a person has a heart attack, it’s important to seek treatment right away to re-open the blocked artery, otherwise, the part of the heart that is nourished by that artery will begin to die. Unlike SCA, which is sudden and sees the heart go into fibrillation (erratic beating), a heart attack can begin hours, days or even weeks before. According to the American Heart Association, heart attack symptoms in women can be different than men.


What are the Signs and Symptoms of Sudden Cardiac Arrest?

When a person goes into SCA, the signs and symptoms are immediate and drastic. They will experience:

  • Sudden collapse;
  • no pulse;
  • no breathing; and
  • loss of consciousness


How to Help Someone Who Goes into Sudden Cardiac Arrest

It’s important to act immediately when a person goes into SCA. Here’s what to do: Dad Club - AED Fundraising

  • Scream for help – ask someone to call 9-1-1 and report back to you to let you know that help is on its way.
  • Find an AED – have someone else (if possible) locate an AED, if there’s one close by;
  • Check the victim’s breathing and Pulse – Put your head over their face and listen for breathing through their nose and mouth while you watch their chest for a rise and fall. Check their neck and wrist for a pulse. If they aren’t breathing and no pulse can be found, prepare to begin CPR
  • Administer CPR; push down on their chest at least 2 inches at a rate of 100 to 120 pushes per minute in the centre of the chest, letting the chest come back up to its normal position after each push;
  • Use an Automated External Defibrillator (AED) – learning how to use an AED is an important first aid skill, however it will guide you through the steps so do not let a lack of training stop you from saving someone’s life; and
  • Keep pushing – After using the AED (or if no AED is available), continue to administer CPR until the victim starts to breathe or move or until EMS arrives.

For more information, read our blog: Responding to an Emergency – A Step-by-Step Guide


Learning basic first aid, CPR and how to use an AED can save a person’s life. When someone goes into SCA, immediate action is required as brain death can occur in as little as three minutes. Knowing what to do can double a person’s chance at survival.