In Switzerland, between 0.4 and 1% of the population suffer cardiovascular arrest every year; that's up to 8,000 people per year. In addition to chest compressions and ventilation, early defibrillation is one of the cornerstones of successful resuscitation. AED devices are surface defibrillators and can therefore not only be operated by specialists. Immediately after the occurrence of such an event, up to 80% of the persons affected would be able to be resuscitated by measures taken immediately. In fact, in 2005, only 5% of patients in Switzerland survived cardiovascular arrest. The geographical distribution of the population and also the bases of the emergency services are very different. Decisive for survival are the rapid alerting of the professional rescue services as well as resuscitation measures started immediately and without interruption. In order to reach persons with a sudden cardiac arrest as fast as possible, the regional rescue services recruited and trained volunteer groups, which in case of emergency are alerted by the emergency medical center 144 Basel. With this application volunteer lay helpers in the region of the emergency are alerted in seconds, which can shorten the therapy-free interval until the arrival of the rescue service massively. With this application more firstresponders can be alerted in less time and faster. In Ticino, the probability of survival in sudden cardiac arrest increased to over 40%.