A cardiac arrest is when the heart abruptly stops pumping without warning. When cardiac arrest occurs, no blood can be pumped to the rest of the body. This means that the brain and vital organs are starved of oxygen; the person becomes unconscious and stops breathing or is not breathing normally. A cardiac arrest is a medical emergency. Without chest compressions and the use of a defibrillator, a person in cardiac arrest will not survive.

Cardiac arrest occurs when the heart’s electrical system malfunctions. It is not a heart attack (myocardial infarction). A heart attack is when a blockage in a blood vessel interrupts the flow of oxygen-rich blood to the heart, causing the heart muscle to die.

What causes a cardiac arrest?

Your heart’s electrical system controls the rate and rhythm of its pumping. The immediate cause of sudden cardiac arrest is usually an abnormality in your heart rhythm, known as an arrhythmia.

The most common cause of cardiac arrest is ventricular fibrillation, an arrhythmia where rapid, erratic electrical impulses, cause your heart chambers or ventricles, to quiver uselessly instead of pumping blood.

If blood cannot flow to the brain, the brain becomes starved of oxygen, and the person loses consciousness in seconds. Unless an emergency shock is delivered to the heart to restore its regular rhythm using a machine called a defibrillator, death occurs within minutes. It’s estimated more than 70% of VF victims die before reaching hospital.

Who is at risk?

Cardiac arrest often occurs in active, outwardly healthy people with no known heart disease or other health problems. Most cardiac arrests that occur out of hospital occur in people’s homes, but a cardiac arrest can happen anywhere, at any time.

What are the signs and symptoms of cardiac arrest?

A cardiac arrest happens suddenly and rapidly. It often occurs with no warning. The person in cardiac arrest will:

  • Collapse and fall to the ground
  • Lose consciousness (not rousable, not aware of their surroundings, and not responsive to talk or touch).
  • Not breathing or not breathing normally (gasp for air)

How is a cardiac arrest treated?

Immediately call Triple Zero (000), and start chest compressions (CPR) and use a defibrillator if there’s one nearby. Follow the instructions from the 000 operator until emergency services arrive and take over.

What you can do to help fight sudden cardiac arrest?

Bystander CPR more than doubles the chance of surviving a cardiac arrest. EVERY MINUTE COUNTS. Learning CPR and how to use a defibrillator (AED) is one of the most important things you can do to fight SCA and save the life of another person.

Learn more about our CPR and First Aid courses. Classes run 7 days a week at various locations throughout Melbourne or contact us for onsite group training.