CPR success rates vary from 17.5% down to less than 1% (survival to discharge from hospital). A lot of it depends on how ‘well’ you are in the moments just prior to your heart and breathing stopping. If you would like to read more about success rates of CPR, please look at this article.
Many people who survive CPR have to cope with internal haemorrhages, fractures, collapsed lungs, brain injury and severe pain. Some survive in a coma, only to die soon after. This may all sound really horrible to contemplate, but doctors and nurses who have witnessed CPR would not want it for themselves, as this article in the Wall Street journal illustrates.