control unit and are placed on or in the heart or elsewhere on or in the patient 39 s body the control unit modifies the energy applied through electrodes 98 responsive to signals from sensors 70 and 72 and local sense electrodes 74 as described hereinbelow the number of electrodes and sensors as well as the positions thereof are shown in fig1 a by way of example and other sites on heart 20 or in a vicinity thereof are appropriate for placement of some of the electrodes and sensors in other applications of the present invention preferably control unit 90 is implanted in the patient in a manner similar to that used to implant pacemakers or defibrillators known in the art such that after an initial calibration period described hereinbelow the unit is generally able to automatically modify the etc signal it applies to the heart as needed so as to maintain a desired level of performance in many applications standard pacing cardioversion and defibrillation capabilities are additionally incorporated into apparatus 18 fig1 b and 1c are schematic illustrations of other preferred configurations of cardiac control apparatus 18 in accordance with respective preferred embodiments of the present invention fig1 b shows a catheter 166 which conveys a plurality of electrodes 165 167 and 169 to respective sites on the right ventricular septum while fig1 c shows a catheter 266 which conveys a different arrangement of electrodes 265 267 269 and 271 to the septum in another preferred embodiment not shown a catheter passes a basket electrode into the right ventricle so as to apply the etc signal to the septum as.