What Is AED?

The automated external defibrillator (AED) is a medical device that automatically analyzes electrocardiograms of patients in cardiac or respiratory arrest. When necessary, AED can be used to apply defibrillation to the patient in accordance with voice-guidance. In Japan, from July 2004 AED became available to non-medical service workers.

What are ventricular fibrillation and defibrillation?

Ventricular fibrillation refers to the state in which each cardiac cell makes fine and irregular flutters, while the heart pumps little or no blood. Ventricular fibrillation is virtually equal to a state of cardiac arrest.

Defibrillation refers to the application of an electric shock (cardioversion) to a patient whose electrocardiogram waveform expresses that ventricular fibrillation or other abnormality is occurring. To return such patient to the normal state, a strong electric current is instantaneously applied to his/her heart.

Efficacy of early defibrillation

Sudden death caused by cardiac disease (e.g.; myocardial infarction, arrhythmia) is substantially related to cardiac arrest resulting from ventricular fibrillation or pulseless ventricular tachycardia. To return such abnormal conditions to the normal state, applying defibrillation is regarded as the most effective way.

Timing of defibrillation is critical. In the case of ventricular fibrillation, it is said that if no defibrillation is applied, the patient’s survival rate is reduced by 7 to 10% with every passing minute. (Source: American Heart Association (AHA) 2002 Guidelines)

Chain of Survival

Smooth linkage of the “Chain of Survival” is essential for lifesaving.The Chain of Survival comprises four steps: “Early Access” and “Early CPR” by persons who happen to be around a patient requiring emergency medical care (“bystanders”), “Early Defibrillation” by emergency personnel and “Early Advanced Care” by medical institutions. If any of the four steps fails to function appropriately, lifesaving is impossible.

Kyoto City Fire Department is promoting enhanced public awareness by disseminating information on first aid provided by “bystanders.”

Early Access > Early CPR > Early Defibrillation > Early Advanced Care