Consensus statement on layout and delivery of automatic external defibrillator in China

1. Introduction Sudden cardiac death (SCD) refers to sudden death due to a variety of cardiac causes. It is manifested as a sudden loss of consciousness, cardiac arrest, and respiratory arrest and generally shows early symptoms that are atypical and not easily detected[1]. According to a recent study, nearly 544?000 patients suffer from SCD every year in China[2]. Rescue of SCD patients in the shortest time is important as the survival rate will decrease by 7％-10％ if the rescue is delayed for one minute[3]. However, SCD mostly occurs in public places outside the hospital, including public sports places, transportation hubs (such as airports, railway stations, and subway stations), shopping centers, factories, and so on. Therefore, out-of-hospital cardiac arrest (OHCA) is a huge threat to people's lives. "Chain of survival" proposed by the American Heart Association in 2015 emphasized the importance of early call for help, rapid implementation of high-quality cardiopulmonary resuscitation (CPR), and immediate use of an automated external defibrillator (AED) in improving the survival rate of OHCA patients. Studies have shown that conducting CPR within 1 min and AEDs defibrillation within 3 to 5 min can achieve a 50％ to 70％ survival rate for cardiac arrest patients[4]. Therefore, early defibrillation of OHCA patients will markedly increase the survival rate.