There are two types of defibrillator machines. One is the manual defibrillator, in which the health care provider decides the intensity of the electric shock and manually delivers shocks to the chest with paddles. The manual defibrillator can only be used by technicians who are highly trained in recognizing potentially lethal heart rhythms and in using the defibrillation machine. The second type is the automated external defibrillator, a device that includes a computer chip that automatically evaluates the patient's heart rhythm and determines if and how much electricity should be delivered to the struggling heart muscle. The automated external defibrillator decreases the training needed to operate the machine and increases the number of people who can successfully defibrillate a person in cardiac arrest.
Defibrillation is a critical link in the chain of survival for treating cardiac arrest.
However, there are other important links, including an early call to 911 EMS services, early cardiopulmonary resuscitation, defibrillation, and early advanced care. The chain of survival refers to the four crucial links in the emergency treatment of sudden cardiac arrest. Starting these procedures quickly can determine whether a person lives or dies. In most communities, dialing 911 activates the emergency medical system, which dispatches appropriate emergency personnel to the scene. If performed properly, CPR can add a few minutes to the time available for successful defibrillation.