An apparatus for treating tissue of a mammalian body having a generator (16) and a controller (16), the generator (16) adapted to supply electromagnetic energy to form a lesion in the tissue under control of the controller (16), the conductivity of the tissue being characterized by the controller (16), an amount of a conductivity liquid to be supplied to the tissue being determined as a function of the conductivity of the tissue, and injections means (14) for injecting the amount of conductive liquid into the tissue over an interval of time.
