Down and dirty, it's really simple.

When you have a sudden cardiac arrest, you are dead: you are not responsive, your heart is not pumping blood, and you are not breathing - at least not normally, (You might be gasping a few times a minute for a while, but you are not breathing normally.)

There are three possible outcomes:

1. You will remain dead, no matter how fast or well you are treated.
2. Your heart will be persuaded to start beating spontaneously, and you will be discharged from the hospital with major brain functions intact.
3. Your heart will be restarted, but your brain will have suffered so much insult from the oxygen deprivation during the whole process that you will either be unable to perform the activities of daily living without assistance, you will be in a coma, or you will be brain dead.

My preference, in order, is #2, #1, #3.

But what is different about the type 3 outcome victims? Why are they type 3, not type 1 or 2?

It's not an absolute correlation, but the vast majority of outcome 3 victims are people who had a witnessed arrest, someone called 911, and waited for the ambulance.

If nobody witnessed your arrest, the odds of your coming back at all are really slim.

If someone witnessed your arrest, started CPR immediately, and used an AED promptly, your odds of getting discharged with your major brain functions intact are almost ten times the national survival average.

It's when someone witnesses an arrest, calls 911, and waits for the ambulance that the odds of your getting out of the hospital with major brain function intact plummet.

You have a greater than ten percent chance of - at least once in your life - seeing a family member, a friend, a co-worker, a golf buddy, a neighbor die of a cardiac arrest die in front of you. What you do at that point is the greatest single determinant of that victim's future.

Did you notice that we're not talking about witnessing the arrest of some sketchy stranger? That's ten times less likely.

The first thing you can do to maximize your probability of surviving an out-of-hospital sudden cardiac arrest is to make sure that the people most likely to witness your arrest are trained.

The second thing you can do to tilt the odds is to have a personal AED handly - unless you live alone, in which case, my advice is to find a roommate.

Bob