by Wood D
(Cardiopulmonary Arrest)


Cardiac arrest means that the heart suddenly stops beating. It is caused by a problem with the heart's electrical system. Emergency medical care needs to be provided right away. If it is not, the person can quickly die since blood is not being pumped throughout the body.

Cardiac arrest is not the same as a heart attack.

Electrical System of the Heart
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Cardiac arrest may be caused by:

  • A rapid, irregular heart rhythm preventing any circulation of blood (most common cause of sudden cardiac arrest)—ventricular fibrillation
  • A rapid, but regular heart rhythm that, if sustained, may turn into ventricular fibrillation—ventricular tachycardia
  • Dramatic slowing of heart rate due to failure of its pacemaker or severe heart block (interference with electrical conduction)
  • Respiratory arrest
  • Choking or drowning
  • Electrocution
  • Hypothermia
  • Sudden loss of blood pressure
  • Complications from eating disorders
  • Unknown causes

Risk Factors

Things that may increase the risk of cardiac arrest include:

  • Coronary artery disease
  • Heart attack
  • Cardiomyopathy
  • Enlarged heart
  • Congenital heart disease
  • Heart valves that do not function properly
  • Conditions affecting the heart's electrical system
  • Severe metabolic imbalances
  • Adverse drug effects such as from drugs to treat abnormal heart rhythms
  • Lung conditions
  • Trauma to the chest
  • Extensive blood loss
  • Having an eating disorder
  • Excessive overexertion in people with heart disorders
  • Illicit drugs such as cocaine use


Cardiac arrest can cause:

  • Loss of consciousness
  • No breathing
  • No pulse

Before cardiac arrest, some people have:

  • Having chest pain
  • Feeling weak
  • Having a pounding sensation in the chest
  • Feeling faint

Some of these symptoms may happen for weeks before the attack.


Diagnosis is based on the event and ECG that may be taken during treatment. An ECG shows the electrical activity of the heart.


Prompt treatment improves the chance of survival. The 4 steps in the cardiac chain of survival are:

Call for Emergency Medical Services

Call for emergency medical services right away.


Defibrillation sends an electrical shock through the chest. The surge of electricity may help to put the heart into a better rhythm. AEDs are available in many public places. They will instruct users how to use it as soon as they are turned on. If an AED is available, it should be attached as soon as possible.

Start CPR

CPR helps keep blood and oxygen flowing to the heart and brain until other treatment can be given. The heart and brain are easily injured with low oxygen levels. CPR should be given until an AED is brought to the person or emergency help arrives.

Advanced Medical Care

The emergency team and doctors at the hospital will work to restore bloodflow, restart the heart, and decrease risk of more complications. It may include medicine, inserting a tube to open airway, and oxygen.

The body temperature may also be lowered. A lower body temperature may slow or prevent injury to the brain. The body temperature may be kept lower for 12 to 24 hours while the body recovers.


Not all cardiac arrest can be prevented. Seek help right away if you have signs of heart attack or signs above. Follow care plan for any heart condition. Let the medical team know if you are having trouble following the plan.


American Heart Association 

Sudden Cardiac Arrest Association 


Canadian Cardiovascular Society 

The College of Family Physicians of Canada 


About cardiac arrest. American Heart Association website. Available at: Accessed September 13, 2019.

Cardiac arrest in adults. EBSCO DynaMed website. Available at: . Accessed September 13, 2019.

Explore sudden cardiac arrest. National Heart Lung and Blood Institute website. Available at: Accessed September 13, 2019.

Sudden cardiac arrest. Heart Rhythm Society website. Available at: Accessed September 13, 2019.

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