Video on my brother in law
Right here. After playing tennis, he collapsed and went into cardiac arrest. Odds of surviving an arrest outside of a hospital are about 6.7%. But they had a portable defib unit on site and a cardiologist in the clubhouse, plus he had a playing partner that knew the latest form of CPR. So a week after he "died," he was back home, aching from a quadruple bypass. There's some quite useful info on operating the most recent and most automated defib units.