Expert: Walter Hintz - 1/26/2006

Question
Thank you, but do you know what part of a second in time does the blood stop in the heart, blood to organs, oxygen to brain, unconsciousness occurs.  I am interested in your answer "matter of seconds" to be more clearly defined.  Looking forward to your reply. -------------------------
Followup To
Question -
How does the body shut down when we "Die Instantly" as in a car accident?
Answer -
Hi Debra: Instant death is kind of a misnomer.  In most states death is defined as the cessation of brain activity commonly called flatlining and it does not occur instantly.  Once the heart stops the oxygen supply is cut off to the brain and unconciousness occurs in a matter of seconds and the brain cells begin to die.  The term instant death can be applied when consciousness is terminated with no chance of it returning. We can safely say for example that decapitation causes instant death.

Answer
Hi Debra;  I do not know if we can be as precise as you want because there are variable factors involved.  If the heart fails to contract than immediately the brain receives no blood and unconsciousness will occur in about 4 seconds. This is about as precise as I can be.   This does not mean the the individual is dead at this time since the brain cells will not die so soon.  How long they will function depends upon other factors. There is still blood in the brain tissue and that blood still contains oxygen.
 We know that the  the brain can be deprived of Oxygen for some minutes before the damage is irreparable.  If the body temperature is very low than the time increases.  Think of a person drowning in ice water.  They can be brought back after a long period.
 For practical purpose we can say that at any given moment you may have three or four seconds to live because if your heart stops and you lose consciousness you may not be revived.