Sudden Cardiac Death (SCD) and Cardiac Arrest

Cardiac arrest, also known as sudden cardiac death (SCD), occurs when an abnormal and very rapid heart rhythm such as VT or VF prevents the heart from pumping normally to deliver blood to the brain and other vital organs. SCD is a condition in which the heart effectively, suddenly stops beating. If the heart stops beating, blood stops flowing to the brain and other vital organs. SCD usually causes death if it’s not treated within minutes. SCD is not the same as a heart attack, although a person can be at a higher risk for SCD during or after a heart attack (myocardial infarction- see ischaemic heart disease).

If someone is experiencing a cardiac arrest, emergency basic (CPR, cardiopulmonary resuscitation) and advanced cardiac life support is required to resuscitate the patient. Members of the public are encouraged to learn CPR and courses teaching this important set of skills are available through St John Ambulance, at If you witness someone having a cardiac arrest, call 000. Survivors of cardiac arrest need to be investigated and treated for the underlying cause, to prevent recurrent events.