There is provided piezoelectric devices for restoring normal contraction rhythms of a heart, or for pacing a heart, comprising a housing, a piezoelectric generator seated within the housing and having first and second electrical conductors wherein the first conductor is connected to an electrically conducting portion of the housing, an electrically conductive skin contact electrode wherein the electrode is electrically insulated from the conducting portion of the housing and is connection with the second conductor, and an actuator for actuating the piezoelectric generator to generate an electrical current in response to stimuli from a user. There is further provided methods for restoring normal contraction rhythms of a heart in cardiac arrest, or for pacing a heart, comprising the administering an electric shock from a piezoelectric device to the chest area of a mammal proximal the heart. The use of a piezoelectric device for such functions is also provided.