The invention provides systems, methods, and apparatus for use in ablation procedures. The invention includes a generator with at least one indifferent lead and at least one catheter lead for connecting an indifferent electrode and a catheter provided with at least one electrode, a charging unit arranged to charge an amount of electrical energy and to discharge an electrical pulse of a predetermined magnitude between the two electrode leads, a power supply arranged to supply electrical energy to the charging unit, an input unit arranged for inputting an indication of the magnitude of the pulse, and a measuring unit arranged between the electrode leads for measuring at least one electrical property between the leads. Numerous additional aspects are provided.