A cardiac defibrillator comprises electrical wires or terminals (24) connected with or configured to connect with defibrillation electrode pads (22), and an electrical circuit (32, 32a, 32b) including an electrical storage element (52) and a piezo-electric transformer (50) arranged to charge the electrical storage element to a voltage effective for delivering a cardiac defibrillation shock. The electrical circuit is configured to discharge the electrical storage element across the electrical wires or terminals to deliver a cardiac defibrillation shock to the electrical wires or terminals.
