Sudden cardiac arrest can happen at any time, and anywhere, and that is why there are different types of defibrillators, for different circumstances and first responders to use. earlier use of an automated external defibrillator (AED) in a cardiac emergency may be the only way to save a life. versatility in gear is important to the circumstance at hand, and that is why Medtronic, Inc. has offered different forms of LifePak defibrillators.