what exactly does brain dead mean?

I'm so sorry to hear that. Anyone is capable of having a herta attack, just certain unhealthy behaviours will increase the risk. When you have a heart attack, part of the heart will die as the blood vessels around that part will get blocked and so can't provide the nutrients and oxygen that the heart needs. This can alaso have a knock on effect on the brain, especially if a clot from the heart travels to the brain and gets stuck there, where it will damage part of the brain. Also, if the brain was starved of oxygen for any length of time it would also suffer. When someone is classed as 'brain dead' it means that there is no brain activity going on anymore and this cannot be reversed. Any damage will stay there and if there is no activity at all ('brain dead') then it sounds like your relative will not survice without medical equipment to keep him alive. I'm so sorry for you.

They explained this on the show The Doctors yesterday, in reference to what happened to Natasha Richardson. There is probably more information on this on their website. The doctors explained that there was no response by her brain to stimuli of any kind for example. I am pretty sure when a doctor tells you that it's the end. Sorry :(

If he actually is brain dead. He is not coming back. The machines are the only thing keeping his body functioning. No electrical activity in the brain. No brain waves.

Brain dead means that there is not enough electrical activity going on in the brain to sustain life

Some people come out of a coma and some do not.Some people are in a coma for a long time.

Doctors really so not understand much about coma .And there is lack of goverment money into studies like this.