Sudden Cardiac Arrest (SCA)

SCA Chain of Survival

Sudden Cardiac Arrest occurs when the heart stops beating suddenly. It can be recognised in a person who has collapsed and is unresponsive with no normal breathing or pulse.

Cardiac Arrest occurs as a result of a life threatening electrical disturbance of the heart beat. This results in a failure of the heart to pump blood to the brain and other vital organs. Immediate action is needed in order to prevent death.


Causes of Sudden Cardiac Arrest

  • Heart Attack - this is the most common cause of SCA. A heart attack occurs when an artery supplying blood to the heart muscle becomes blocked. This can result in an irregular lethal heart beat which can lead to Cardiac Arrest. Click here to learn more about heart attack
  • Heart Muscle Disease - abnormalities of the heart muscle can also lead to the malfunction of the heartbeat
  • Abnormalities of the Heart Rhythm - disease of the electrics of the heart rhythm (Arrhythmia) can lead to a sudden and potentially lethal irregularity of the heartbeat
  • Other Causes - Drowning, Choking, Electrocution, Blunt Chest Trauma, Accident & adverse drug reaction including illicit drug use and poisoning.
  • Unexplained - Some Sudden Cardiac Arrests remain unexplained.



Currently a person’s chance of surviving a cardiac arrest is thought to be a dismal 1%. This can be linked to a breakdown in the chain of survival. This chain of survival incorporates five critical steps which should be taken in order to increase the victim's chance of survival.


The Chain of Survival

1. Early Access, (Recognising the emergency, Phone 999 or 112, get AED)
2. Early CPR
3. Early Defibrillation
4. Early Advanced Care
5. Integrated post–cardiac arrest care
The effectiveness of the Chain of Survival is hampered when people fail to recognise emergencies promptly and delay calling an ambulance. A lack of CPR training and access to defibrillators further diminishes the victim's chance of survival.


Croí is a registered Irish heart & stroke charity dedicated to the fight against heart disease and stroke, with a special focus on the West of Ireland. 

Our Mission is to 'Prevent Disease, Save Lives, Promote Recovery and Wellbeing'

The charity is totally funded through the proceeds of fundraising events, voluntary contributions and philanthropy.
Charity Number: CHY7500

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