Abstract: An apparatus and method for determining cardiac performance in a patient. The apparatus includes a multifrequency conductance catheter for measuring instantaneous volume of a heart chamber with multifrequencies. The apparatus includes a mechanism for measuring instantaneous pressure of the heart chamber. The apparatus includes a mechanism for separating the multifrequencies. The apparatus includes a mechanism for signal processing the instantaneous volume and the pressure of the heart chamber to identify mechanical strength of the chamber and for automatically producing a plurality of desired waveforms at desired frequencies for the conductance catheter. The processing mechanism is connected to the pressure measuring mechanism, the separating mechanism and the volume measuring mechanism.