Sudden Cardiac Death

Atrial Fibrillation | Syncope | Sudden Cardiac Death


Sudden Cardiac Death happens when the heart unexpectedly stops working. SCD is usually caused by an abnormal heart rhythm (arrhythmia). When a person experiences SCD, he or she collapses, is unresponsive to touch or sound and usually stops breathing. SCD victims will die if they don’t receive emergency medical help. An Automatic External Defibrillator (AED) must be used to restart the heart. 

Each year up to 40,000 cardiac arrests happen in Canada.

Your heart has a natural pacemaker, called the sinus node, which creates electrical impulses that cause your heart to beat. When there is a disorder in this electrical system, an arrhythmia may occurs.


SCD occurs more frequently in people with heart disease, but may occasionally occur in active, healthy people who aren’t aware they have heart disease or other health problems. 

SCD is usually caused by arrhythmias, and these arrhythmias may be triggered by other issues, including:

  • Coronary heart disease
  • Heart attacks
  • Congenital heart disease
  • Other forms of heart disease (often undiagnosed)
  • Electrocution
  • (In children) Respiratory failure or shock

Factors that may increase the risk of SCD include:

  • A previous episode of SCD
  • Family history of SCD
  • A previous heart attack
  • A personal or family history of heart disease
  • Age
  • Use of illegal drugs
  • Nutritional imbalance, such as low potassium or magnesium levels

If your doctor is concerned about the risk of SCD, the following tests may be ordered: 

  • Electrocardiogram
  • Echocardiogram
  • Holter monitor
  • Event monitor
  • Electrophysiology study  

SCD may be prevented through medication, an implantable cardioverter defibrillator, or catheter ablation.

Reduce The Risk

  • Stay active
  • Eat healthy foods
  • Maintain a healthy weight
  • Stop smoking
  • Monitor and treat conditions such as high blood pressure, high cholesterol and diabetes

What to do

It’s important to act quickly when you see a Sudden Cardiac Death happen. The use of Cardiopulmonary Resuscitation (CPR) and an Automatic External Defibrillator (AED) can make a big difference.

If you see an SCD happen:

  • Tell someone to call 911 or your local emergency response number.
  • Get an AED if one is available.
  • If the person isn’t breathing or is only gasping, start Cardiopulmonary Resuscitation (CPR). Push down in the center of the chest 30 times. Push hard and push fast.
  • Use the AED as soon as it arrives by turning it on and following the prompts.
  • Keep pushing until the person starts to breathe or move, or someone with more advanced training takes over.

How to get involved

Contact us if you are interested in becoming involved in arrhythmia research and you fit the following criteria:
– Have significant experience of living with an arrhythmia
– Are in a period of stable health
– Have a constructive critical attitude and a certain distance from your own story
– Are willing to help people by working with both patients and health professionals and researchers

Contact Us