ABSTRACT
Defibrillators are devices used to supply a strong electric shock (often referred to as a countershock) to a patient in an effort to convert excessively fast and ineffective heart rhythm disorders to slower rhythms that allow the heart to pump more blood. External defibrillators have been in common use for many decades for emergency treatment of life-threatening cardiac rhythms as well as for elective treatment of less threatening rapid rhythms. Figure 57.1 shows an external defibrillator.
