An apparatus for the cardio-synchronized stimulation of skeletal or smooth muscle, but excluding the heart muscles, in a counterpulsation mode of a patient. The apparatus comprises an active and a passive electrode for attachment to said patient, a signal processor having a configuration input for varying a time delay associated with counterpulsation mode stimulation, and a sensing system for sensing information relating to the performance of the patient's heart and for transmission of information signals to said signal processor, said signal processor producing control signal information relating to stimulation signals to be applied to said active electrode in a counterpulsation mode, a stimulation signal generator associated with said active electrode for generating stimulation signals, wireless transmission means for transmitting said control signal information from said signal processor to said stimulation signal generator whereby said stimulation signal generator applies stimulation signals to said active electrode in accordance with said signal information.