Here in New York, schools have been required to have an AED on site since 2002.
Under Public Health Law 3000-b all school districts, BOCES, county vocational education and extension boards, and charter schools must provide and maintain on-site, in each instructional school facility, at least one functional automated external defibrillator (AED) for use during emergencies. The legislation also requires public school officials and administrators responsible for such school facilities to ensure the presence of at least one staff person who is trained in the operation and use of an AED.

Obviously it's not going to help all the time but it certainly won't help if it isn't there. We have them mounted right outside the gyms.