An apparatus for applying at least one electric pulse to a living myocardial tissue comprises an input receiving an electric signal representing a present electric activity of the myocardial tissue a signal processor (11) processing the electric signal to determine a measure of the present complexity of the electric signal in the state space and to output a control signal (13) when the complexity measure is lower than a predetermined complexity threshold value a pulse generator configured to generate the at least one electric pulse in response to the control signal and an output configured to output the at least one electric pulse to the myocardial tissue.
