Abstract: A method for measuring the complex impedance spectrum of a portion of the myocardium by placing two electrodes on a portion of the myocardium and applying a current pulse to the electrodes to generate a voltage response between the electrodes. Both the current pulse and voltage response are sampled and digitized and then a Fast fourier transform is taken of both the current pulse and the voltage response to obtain a complex current pulse spectrum and a complex voltage response spectrum. Next, the complex voltage response spectrum is divided by the complex current pulse spectrum to obtain the complex impedance spectrum.