What is Cardiac Arrest?

By Dr. Ananya Mandal, MDReviewed by Sally Robertson, B.Sc.

A cardiac arrest is also called a cardiopulmonary arrest or circulatory arrest and indicates a sudden stop in effective and normal blood circulation due to failure of the heart to pump blood.

Cardiac arrest is different from myocardial infarction or heart attack but may be caused by a heart attack. When the blood flow to the heart is stopped due to narrow or obstructed coronary arteries, a heart attack occurs. This may lead to a cardiogenic shock and cardiac arrest.

What happens in cardiac arrest

1. Once the usual blood circulation stops, oxygen delivery to all vital organs is also stopped. The organ that is the most quickly and severely affected by this is the brain. The patient loses consciousness and breathing is shallow and minimized. If the cardiac arrest persists for over five minutes, permanent brain damage may occur.
2. The pulse that is usually seen in the carotid artery in the neck as well in the wrists and ankles is lacking.
3. Cardiac arrest may lead to sudden cardiac death or SCD. Heart attack is an important cause of SCD.

Causes of cardiac arrest

Some of the most important causes of cardiac arrest include:

• Heart attack or myocardial infarction (seen in 30% of cases)
• Cardiac anatomical abnormality
• Cardiac rhythm disturbance or arrhythmia. The most common fatal abnormal heart rhythm is ventricular fibrillation.
• Cardiomyopathy
• Sepsis and major infection
• Drug overdose
• Major injury and blood loss. Lung or heart injury may also lead to cardiac arrest.
• Advanced cancer
• Extremely high or low body temperature
• Extremely high or low blood level of potassium
• Severe oxygen deprivation
• Pulmonary embolism

What needs to be done?

A cardiac arrest is a medical emergency. For every minute that a person is in cardiac arrest before arrival of a defibrillator, the chances of survival are reduced by about 10%. Cardiopulmonary resuscitation is attempted along with defibrillation of the heart to try and reinstate the heart's pumping rhythm.

To provide adequate CPR, a person needs to check that:

A = Airways are open by tilting the head back and lifting the chin of the patient

B = Breathing signs can be seen and heard

C = Circulation is attempted with cardiac compression

Further Reading

• All Cardiac Arrest Content
• Cardiac Arrest Treatment
• Cardiac Arrest Prognosis
• Cardiac Arrest Prevention
• Cardiac Arrest Ethical Issues