Method and apparatus for detecting electric energy delivered to the heart of a body when performing defibrillation. The method comprises the steps of applying a defibrillator with electrodes placed on opposite sides of the heart applying an apparatus on the body and between said electrodes for detecting and measuring electric and/or magnetic fields performing defibrillation by delivering electric energy to the body detecting electric energy running through the heart with said apparatus, and indicating electric energy applied to the heart. The apparatus for performing the method comprises detection and indications means for performing the method.
