In Italian hospitals, 85% of patients hospitalized in general medical wards who experience cardiac arrest die, while the incidence is much lower in patients in intensive care units. Defibrillation, in Italian hospitals, often occurs very late, either due to a lack of defibrillators, or due to architectural and structural barriers. The object of an in-hospital emergency service is to prevent and treat cardiac arrest without subsequent complications, such as brain damage, renal failure etc. The Naples Heart Project was based on a feasibility study of the in-hospital emergency service to evaluate and analyze problems associated with type of structure, departmental and institutional dislocation, internal practicability (architectural features and preferential ways), staff numbers and distribution, the calling system for emergency, and the equipment available. The Naples Heart Project began in July 2001, since then it has already created 835 BLSD first responders among the hospital staff; 440 were physicians and physicians still in training, 310 were nurses and 85 were administrative staff.