Automated external defibrillators: technical considerations and clinical promise.

Early defibrillation is the most important determinant of survival for victims of cardiac arrest due to ventricular fibrillation. The automated external defibrillator (AED) was developed as the result of the American Heart Association's Public Access Defibrillation initiative. The goal of this initiative is to place AEDs in strategic locations so that laypersons with minimal training could promptly defibrillate victims of cardiac arrest. Because of changes in design and the use of alternative waveforms for defibrillation, the modern AED is compact and portable, simple to use, and highly efficacious; in addition, it requires little maintenance. Automated external defibrillators have been used successfully by traditional and nontraditional responders as well as laypersons. In special environments, such as casinos and commercial aircraft, AEDs have performed particularly well. State and federal legislation has eased concerns about AED use by extending legal protection to AED users under Good Samaritan laws. Since the experience continues to be positive, AEDs are being used in increasingly diverse community locations, and public awareness is growing. The American Heart Association's initiative is progressing rapidly.