It's important to note: that death is most likely to occur after 10 minutes of loss of oxygen to the brain. From 6 to 10 minutes brain damage is expected. From 4 to 6 minutes brain damage is very possible and from 0 to 4 minutes brain damage is virtually non-existent.
When the heart stops beating blood stops flowing throughout the body. Cardiopulmonary Resuscitation (CPR) is when a person performs chest compressions and breathing into a patient who has no pulse or who isn’t breathing. Chest compressions combined with breathing into the patient will carry the now oxygenated blood throughout the body and into the brain. CPR acts like an artificial heart moving the blood rich in oxygen to the brain.
The patient's survival rate increases as he/she receives CPR, an Automated External Defibrillator (AED), and if Emergency Medical Services (EMS) arrives within 10 minutes.
Untrained rescuers should provide Compression-only CPR since it's easy for an operator (dispatcher) to provide and guide instructions over the telephone. Remember, it is a priority to activate the Emergency Response System immediately and to provide chest compressions..