"Defibrillation," Scully said automatically. "Yes, what they're doing is kind of, mmmm. Re-setting the heart, in case of irregular rhythm or heart stoppage. It shocks the heart back into its natural rhythm, at least long enough to get them more help." She frowned. "I should have brought an AED (http://en.wikipedia.org/wiki/Automated_external_defibrillator) with me to show you guys how to do that too. Most of the automatic ones can diagnose how much voltage to use on someone if their heartbeat is irregular."