The guidelines for this forum do not allow for the detailed response you have requested. I suggest that you visit the following, American Heart Association, website: http://www.heart.org/HEARTORG/Conditions/More/CardiacArrest/Cardiac-Arrest_UCM_002081_SubHomePage.jsp
The following is also an excellent resource; one that addresses almost all your questions: http://www.news-medical.net/health/What-is-Cardiac-Arrest.aspx